1. How to extract a file extension in php?

Old method was
$path_info = pathinfo('/images/myPicture.gif');
echo $path_info['extension']; //will print gif

New way is
$filename = '/images/myPicture.gif';
$ext = pathinfo($filename, PATHINFO_EXTENSION);
echo $ext;//will print gif

2. How to use cryptographic security in php?

If you need some pseudorandom bits for security or cryptographic purposes (e.g.g., random IV for block cipher, random salt for password hash) mt_rand() is a poor source. On most Unix/Linux and/or MS-Windows platforms you can get a better grade of pseudorandom bits from the OS or system library, like this:

// get 128 pseudorandom bits in a string of 16 bytes

$pr_bits = '';

// Unix/Linux platform?
$fp = @fopen('/dev/urandom','rb');
if ($fp !== FALSE) {
$pr_bits .= @fread($fp,16);
@fclose($fp);
}

// MS-Windows platform?
if (@class_exists('COM')) {
// http://msdn.microsoft.com/en-us/library/aa388176(VS.85).aspx
try {
$CAPI_Util = new COM('CAPICOM.Utilities.1');
$pr_bits .= $CAPI_Util->GetRandom(16,0);

// if we ask for binary data PHP munges it, so we
// request base64 return value. We squeeze out the
// redundancy and useless ==CRLF by hashing...
if ($pr_bits) { $pr_bits = md5($pr_bits,TRUE); }
} catch (Exception $ex) {
// echo 'Exception: ' . $ex->getMessage();
}
}

if (strlen($pr_bits) < 16) {
// do something to warn system owner that
// pseudorandom generator is missing
}
?>
NB: it is generally safe to leave both the attempt to read /dev/urandom and the attempt to access CAPICOM in your code, though each will fail silently on the other's platform. Leave them both there so your code will be more portable.

3. How To Read the Entire File into a Single String?

If you have a file, and you want to read the entire file into a single string, you can use the file_get_contents() function. It opens the specified file, reads all characters in the file, and returns them in a single string. Here is a PHP script example on how to file_get_contents():

<?php
$file = file_get_contents("/windows/system32/drivers/etc/services");
print("Size of the file: ".strlen($file)."n");
?>

This script will print:

Size of the file: 7116

4. How many ways can we get the value of current session id?

session_id() returns the session id for the current session.

5. What is the difference between include and require?

It's how they handle failures. If the file is not found by require(), it will cause a fatal error and halt the execution of the script. If the file is not found by include(), a warning will be issued, but execution will continue.

6. Explain the ternary conditional operator in PHP?

Expression preceding the ? is evaluated, if it's true, then the expression preceding the : is executed, otherwise, the expression following : is executed.

7. How To Turn On the Session Support in PHP?

The session support can be turned on automatically at the site level, or manually in each PHP page script:

* Turning on session support automatically at the site level: Set session.auto_start = 1 in php.ini.
* Turning on session support manually in each page script: Call session_start() funtion.

8. How can I embed a java program in php file and what changes have to be done in php.ini file?

There are two possible ways to bridge PHP and Java: you can either integrate PHP into a Java Servlet environment, which is the more stable and efficient solution, or integrate Java support into PHP. The former is provided by a SAPI module that interfaces with the Servlet server, the latter by this Java extension.
The Java extension provides a simple and effective means for creating and invoking methods on Java objects from PHP. The JVM is created using JNI, and everything runs in-process.

Example Code:

getProperty('java.version') . ''; echo 'Java vendor=' . $system->getProperty('java.vendor') . ''; echo 'OS=' . $system->getProperty('os.name') . ' ' . $system->getProperty('os.version') . ' on ' . $system->getProperty('os.arch') . ' '; // java.util.Date example $formatter = new Java('java.text.SimpleDateFormat', "EEEE, MMMM dd, yyyy 'at' h:mm:ss a zzzz"); echo $formatter->format(new Java('java.util.Date')); ?>

The behavior of these functions is affected by settings in php.ini.
Table 1. Java configuration options
Name
Default
Changeable
java.class.path
NULL
PHP_INI_ALL
Name Default Changeable
java.home
NULL
PHP_INI_ALL
java.library.path
NULL
PHP_INI_ALL
java.library
JAVALIB
PHP_INI_ALL

9. Explain about Type Juggling in php?

PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined by the context in which that variable is used. That is to say, if you assign a string value to variable $var, $var becomes a string. If you then assign an integer value to $var, it becomes an integer.

An example of PHP's automatic type conversion is the addition operator '+'. If any of the operands is a float, then all operands are evaluated as floats, and the result will be a float. Otherwise, the operands will be interpreted as integers, and the result will also be an integer. Note that this does NOT change the types of the operands themselves; the only change is in how the operands are evaluated.

$foo += 2; // $foo is now an integer (2)
$foo = $foo + 1.3; // $foo is now a float (3.3)
$foo = 5 + "10 Little Piggies"; // $foo is integer (15)
$foo = 5 + "10 Small Pigs"; // $foo is integer (15)

If the last two examples above seem odd, see String conversion to numbers.
If you wish to change the type of a variable, see settype().
If you would like to test any of the examples in this section, you can use the var_dump() function.
Note: The behavior of an automatic conversion to array is currently undefined.

Since PHP (for historical reasons) supports indexing into strings via offsets using the same syntax as array indexing, the example above leads to a problem: should $a become an array with its first element being "f", or should "f" become the first character of

10. What is the difference between Reply-to and Return-path in the headers of a mail function?

Reply-to: Reply-to is where to delivery the reply of the mail.

Return-path: Return path is when there is a mail delivery failure occurs then where to delivery the failure notification.

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11. What type of headers have to be added in the mail function to attach a file?

$boundary = '--' . md5( uniqid ( rand() ) );
$headers = "From: "Me"n";
$headers .= "MIME-Version: 1.0n";
$headers .= "Content-Type: multipart/mixed; boundary="$boundary"";

12. What changes I have to do in php.ini file for file uploading?

Make the following line uncomment like:
; Whether to allow HTTP file uploads.
file_uploads = On
; Temporary directory for HTTP uploaded files (will use system default if not
; specified).
upload_tmp_dir = C:apache2triadtemp
; Maximum allowed size for uploaded files.
upload_max_filesize = 2M

13. What is the default session time in php and how can I change it?

The default session time in php is until closing of browser

14. How many ways we can give the output to a browser?

HTML output
PHP, ASP, JSP, Servlet Function
Script Language output Function
Different Type of embedded Package to output to a browser

15. How can I use the COM components in php?

The COM class provides a framework to integrate (D)COM components into your PHP scripts.
string COM::COM( string module_name [, string server_name [, int codepage]]) - COM class constructor.

Parameters:

module_name: name or class-id of the requested component.
server_name: name of the DCOM server from which the component should be fetched. If NULL, localhost is assumed. To allow DCOM com, allow_dcom has to be set to TRUE in php.ini.
codepage - specifies the codepage that is used to convert php-strings to unicode-strings and vice versa. Possible values are CP_ACP, CP_MACCP, CP_OEMCP, CP_SYMBOL, CP_THREAD_ACP, CP_UTF7 and CP_UTF8.
Usage:
$word->Visible = 1; //open an empty document
$word->Documents->Add(); //do some weird stuff
$word->Selection->TypeText("This is a test…");
$word->Documents[1]->SaveAs("Useless test.doc"); //closing word
$word->Quit(); //free the object
$word->Release();
$word = null;

16. How can increase the performance of MySQL select query?

We can use LIMIT to stop MySql for further search in table after we have received our required no. of records, also we can use LEFT JOIN or RIGHT JOIN instead of full join in cases we have related data in two or more tables.

17. What type of inheritance that php supports?

In PHP an extended class is always dependent on a single base class, that is, multiple inheritance is not supported. Classes are extended using the keyword 'extends'.

18. Explain normalization concept?

The normalization process involves getting our data to conform to three progressive normal forms, and a higher level of normalization cannot be achieved until the previous levels have been achieved (there are actually five normal forms, but the last two are mainly academic and will not be discussed).

First Normal Form
The First Normal Form (or 1NF) involves removal of redundant data from horizontal rows. We want to ensure that there is no duplication of data in a given row, and that every column stores the least amount of information possible (making the field atomic).

Second Normal Form
Where the First Normal Form deals with redundancy of data across a horizontal row, Second Normal Form (or 2NF) deals with redundancy of data in vertical columns. As stated earlier, the normal forms are progressive, so to achieve Second Normal Form, your tables must already be in First Normal Form.

Third Normal Form
I have a confession to make; I do not often use Third Normal Form. In Third Normal Form we are looking for data in our tables that is not fully dependent on the primary key, but defendant on another value in the table

19. What is maximum size of a database in mysql?

If the operating system or filesystem places a limit on the number of files in a directory, MySQL is bound by that constraint. The efficiency of the operating system in handling large numbers of files in a directory can place a practical limit on the number of tables in a database. If the time required to open a file in the directory increases significantly as the number of files increases, database performance can be adversely affected.
The amount of available disk space limits the number of tables.
MySQL 3.22 had a 4GB (4 gigabyte) limit on table size. With the MyISAM storage engine in MySQL 3.23, the maximum table size was increased to 65536 terabytes (2567 - 1 bytes). With this larger allowed table size, the maximum effective table size for MySQL databases is usually determined by operating system constraints on file sizes, not by MySQL internal limits.
The InnoDB storage engine maintains InnoDB tables within a tablespace that can be created from several files. This allows a table to exceed the maximum individual file size. The tablespace can include raw disk partitions, which allows extremely large tables. The maximum tablespace size is 64TB.

20. What are the advantages of stored procedures, triggers, indexes in PHP?

A stored procedure is a set of SQL commands that can be compiled and stored in the server. Once this has been done, clients don't need to keep re-issuing the entire query but can refer to the stored procedure. This provides better overall performance because the query has to be parsed only once, and less information needs to be sent between the server and the client. You can also raise the conceptual level by having libraries of functions in the server. However, stored procedures of course do increase the load on the database server system, as more of the work is done on the server side and less on the client (application) side. Triggers will also be implemented. A trigger is effectively a type of stored procedure, one that is invoked when a particular event occurs. For example, you can install a stored procedure that is triggered each time a record is deleted from a transaction table and that stored procedure automatically deletes the corresponding customer from a customer table when all his transactions are deleted. Indexes are used to find rows with specific column values quickly. Without an index, MySQL must begin with the first row and then read through the entire table to find the relevant rows. The larger the table, the more this costs. If the table has an index for the columns in question, MySQL can quickly determine the position to seek to in the middle of the data file without having to look at all the data.

21. What are the difference between abstract class and interface?

Abstract class: abstract classes are the class where one or more methods are abstract but not necessarily all method has to be abstract. Abstract methods are the methods, which are declare in its class but not define. The definition of those methods must be in its extending class.

Interface: Interfaces are one type of class where all the methods are abstract. That means all the methods only declared but not defined. All the methods must be define by its implemented class.

22. How can I make a script that can be bilingual (supports English, German)?

You can change charset variable in above line in the script to support bilanguage.

23. How can we get second of the current time using date function?

$second = date("s");

24. What is the use of friend function in PHP?

Friend functions
Sometimes a function is best shared among a number of different classes. Such functions can be declared either as member functions of one class or as global functions. In either case they can be set to be friends of other classes, by using a friend specifier in the class that is admitting them. Such functions can use all attributes of the class which names them as a friend, as if they were themselves members of that class.
A friend declaration is essentially a prototype for a member function, but instead of requiring an implementation with the name of that class attached by the double colon syntax, a global function or member function of another class provides the match.
class mylinkage
{
private:
mylinkage * prev;
mylinkage * next;

protected:
friend void set_prev(mylinkage* L, mylinkage* N);
void set_next(mylinkage* L);

public:
mylinkage * succ();
mylinkage * pred();
mylinkage();
};

void mylinkage::set_next(mylinkage* L) { next = L; }

void set_prev(mylinkage * L, mylinkage * N ) { N->prev = L; }

Friends in other classes
It is possible to specify a member function of another class as a friend as follows:
class C
{
friend int B::f1();
};
class B
{
int f1();
};

It is also possible to specify all the functions in another class as friends, by specifying the entire class as a friend.
class A
{
friend class B;
};

25. What are the current versions of Apache, PHP, and MySQL?

PHP: PHP 5.1.2
MySQL: MySQL 5.1
Apache: Apache 2.1

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26. How can we destroy the cookie in PHP?

Set the cookie with a past expiration time.

27. How can we submit from without a submit button?

Trigger the JavaScript code on any event ( like onSelect of drop down list box, onfocus, etc ) document.myform.submit(); This will submit the form.

28. How can I know that a variable is a number or not using a JavaScript?

Answer 1:
bool is_numeric( mixed var)
Returns TRUE if var is a number or a numeric string, FALSE otherwise.

Answer 2:
Definition and Usage
The isNaN() function is used to check if a value is not a number.

Syntax
isNaN(number)

Parameter Description
number Required. The value to be tested

29. WHAT TYPES OF IMAGES THAT PHP SUPPORTS?

Using imagetypes() function to find out what types of images are supported in your PHP engine.
imagetypes() - Returns the image types supported.
This function returns a bit-field corresponding to the image formats supported by the version of GD linked into PHP. The following bits are returned, IMG_GIF | IMG_JPG | IMG_PNG | IMG_WBMP | IMG_XPM.

30. How to reset/destroy a cookie in PHP?

Reset a cookie by specifying expire time in the past:
Example: setcookie('Test',$i,time()-3600); // already expired time

Reset a cookie by specifying its name only
Example: setcookie('Test');

31. How to set cookies in PHP?

setcookie('variable','value','time')
;
variable - name of the cookie variable
value - value of the cookie variable
time - expiry time
Example: setcookie('Test',$i,time()+3600);

Test - cookie variable name
$i - value of the variable 'Test'
time()+3600 - denotes that the cookie will expire after an one hour

32. How can we increase the execution time of a php script?

By the use of void set_time_limit(int seconds)
Set the number of seconds a script is allowed to run. If this is reached, the script returns a fatal error. The default limit is 30 seconds or, if it exists, the max_execution_time value defined in the php.ini. If seconds is set to zero, no time limit is imposed.

When called, set_time_limit() restarts the timeout counter from zero. In other words, if the timeout is the default 30 seconds, and 25 seconds into script execution a call such as set_time_limit(20) is made, the script will run for a total of 45 seconds before timing out.

33. What is the functionality of the function htmlentities?

htmlentities() - Convert all applicable characters to HTML entities
This function is identical to htmlspecialchars() in all ways, except with htmlentities(), all characters which have HTML character entity equivalents are translated into these entities.

34. What are encryption functions in PHP?

CRYPT()
MD5()

35. What are the functions for IMAP?

imap_body - Read the message body
imap_check - Check current mailbox
imap_delete - Mark a message for deletion from current mailbox
imap_mail - Send an email message

36. How can we encrypt and decrypt a data presented in a table using MySQL?

You can use functions: AES_ENCRYPT() and AES_DECRYPT() like:

AES_ENCRYPT(str, key_str)
AES_DECRYPT(crypt_str, key_str)

37. What is meant by nl2br()?

Anwser1:
nl2br() inserts a HTML tag <br> before all new line characters n in a string.

echo nl2br("god bless n you");

output:
god bless<br>
you

38. What is the difference between PHP4 and PHP5?

PHP4 cannot support oops concepts and Zend engine 1 is used.

PHP5 supports oops concepts and Zend engine 2 is used.
Error supporting is increased in PHP5.
XML and SQLLite will is increased in PHP5.

39. What are the MySQL database files stored in system ?

Data is stored in name.myd
Table structure is stored in name.frm
Index is stored in name.myi

40. What are the differences between mysql_fetch_array(), mysql_fetch_object(), mysql_fetch_row()?

Answer 1:
mysql_fetch_array() -> Fetch a result row as a combination of associative array and regular array.
mysql_fetch_object() -> Fetch a result row as an object.
mysql_fetch_row() -> Fetch a result set as a regular array().


Answer 2:
The difference between mysql_fetch_row() and mysql_fetch_array() is that the first returns the results in a numeric array ($row[0], $row[1], etc.), while the latter returns a the results an array containing both numeric and associative keys ($row['name'], $row['email'], etc.). mysql_fetch_object() returns an object ($row->name, $row->email, etc.).

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41. How can we know that a session is started or not?

A session starts by session_start() function.
This session_start() is always declared in header portion. it always declares first. then we write session_register().

42. What is the difference between GROUP BY and ORDER BY in SQL?

To sort a result, use an ORDER BY clause.
The most general way to satisfy a GROUP BY clause is to scan the whole table and create a new temporary table where all rows from each group are consecutive, and then use this temporary table to discover groups and apply aggregate functions (if any).
ORDER BY [col1],[col2],...[coln]; Tells DBMS according to what columns it should sort the result. If two rows will hawe the same value in col1 it will try to sort them according to col2 and so on.
GROUP BY [col1],[col2],...[coln]; Tells DBMS to group (aggregate) results with same value of column col1. You can use COUNT(col1), SUM(col1), AVG(col1) with it, if you want to count all items in group, sum all values or view average.

43. What is meant by MIME?

Answer 1:
MIME is Multipurpose Internet Mail Extensions is an Internet standard for the format of e-mail. However browsers also uses MIME standard to transmit files. MIME has a header which is added to a beginning of the data. When browser sees such header it shows the data as it would be a file (for example image)

Some examples of MIME types:
audio/x-ms-wmp
image/png
aplication/x-shockwave-flash


Answer 2:
Multipurpose Internet Mail Extensions.
WWW's ability to recognize and handle files of different types is largely dependent on the use of the MIME (Multipurpose Internet Mail Extensions) standard. The standard provides for a system of registration of file types with information about the applications needed to process them. This information is incorporated into Web server and browser software, and enables the automatic recognition and display of registered file types. …

44. How can we change the data type of a column of a table?

This will change the data type of a column:

ALTER TABLE table_name CHANGE colm_name same_colm_name [new data type]

45. How can we know the number of days between two given dates using MySQL?

Use DATEDIFF()

SELECT DATEDIFF(NOW(),'2008-10-01');

46. How can we change the name of a column of a table?

This will change the name of column:

ALTER TABLE table_name CHANGE old_colm_name new_colm_name

47. What is the functionality of MD5 function in PHP?

string md5(string)

It calculates the MD5 hash of a string. The hash is a 32-character hexadecimal number.

48. How can we encrypt and decrypt a data present in a mysql table using mysql?

AES_ENCRYPT() and AES_DECRYPT()

49. What is the difference between CHAR and VARCHAR data types?

CHAR is a fixed length data type. CHAR(n) will take n characters of storage even if you enter less than n characters to that column. For example, "Hello!" will be stored as "Hello! " in CHAR(10) column.

VARCHAR is a variable length data type. VARCHAR(n) will take only the required storage for the actual number of characters entered to that column. For example, "Hello!" will be stored as "Hello!" in VARCHAR(10) column.

50. Give the syntax of REVOKE commands?

The generic syntax for revoke is as following

REVOKE [rights] on [database] FROM [username@hostname]

Now rights can be:
a) ALL privilages
b) Combination of CREATE, DROP, SELECT, INSERT, UPDATE and DELETE etc.

We can grant rights on all databse by usingh *.* or some specific database by database.* or a specific table by database.table_name.

51. Give the syntax of GRANT commands?

The generic syntax for GRANT is as following

GRANT [rights] on [database] TO [username@hostname] IDENTIFIED BY [password]

Now rights can be:
a) ALL privilages
b) Combination of CREATE, DROP, SELECT, INSERT, UPDATE and DELETE etc.

We can grant rights on all databse by usingh *.* or some specific database by database.* or a specific table by database.table_name.

52. How many ways we can we find the current date using MySQL?

SELECT CURDATE();
SELECT CURRENT_DATE();
SELECT CURTIME();
SELECT CURRENT_TIME();

53. How can we find the number of rows in a result set using PHP?

Here is how can you find the number of rows in a result set in PHP:

$result = mysql_query($any_valid_sql, $database_link);
$num_rows = mysql_num_rows($result);
echo "$num_rows rows found";

54. What is the difference between md5(), crc32() and sha1() crypto on PHP?

The major difference is the length of the hash generated. CRC32 is, evidently, 32 bits, while sha1() returns a 128 bit value, and md5() returns a 160 bit value. This is important when avoiding collisions.

55. How can we find the number of rows in a table using MySQL?

Use this for MySQL

SELECT COUNT(*) FROM table_name;

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56. How many values can the SET function of MySQL take?

MySQL SET function can take zero or more values, but at the maximum it can take 64 values.

57. What is the maximum length of a table name, a database name, or a field name in MySQL?

Database name: 64 characters
Table name: 64 characters
Column name: 64 characters

58. How many ways we can pass the variable through the navigation between the pages?

At least 3 ways:

1. Put the variable into session in the first page, and get it back from session in the next page.
2. Put the variable into cookie in the first page, and get it back from the cookie in the next page.
3. Put the variable into a hidden form field, and get it back from the form in the next page.

59. How can we know the count/number of elements of an array?

2 ways:
a) sizeof($array) - This function is an alias of count()
b) count($urarray) - This function returns the number of elements in an array.
Interestingly if you just pass a simple var instead of an array, count() will return 1.

60. What are the different functions in sorting an array?

Sorting functions in PHP:
asort()
arsort()
ksort()
krsort()
uksort()
sort()
natsort()
rsort()

61. How can we destroy the session, how can we unset the variable of a session?

session_unregister() - Unregister a global variable from the current session
session_unset() - Free all session variables

62. What Is the difference between htmlentities() and htmlspecialchars()?

htmlspecialchars only takes care of <, >, single quote ‘, double quote " and ampersand. htmlentities translates all occurrences of character sequences that have different meaning in HTML.

63. What is the output of the ucwords function in this example?

$formatted = ucwords("GLOBALGUIDELINE IS COLLECTION OF INTERVIEW QUESTIONS");
print $formatted;
What will be printed is GLOBALGUIDELINE IS COLLECTION OF INTERVIEW QUESTIONS.
ucwords() makes every first letter of every word capital, but it does not lower-case anything else. To avoid this, and get a properly formatted string, it's worth using strtolower() first.

64. I am writing an application in PHP that outputs a printable version of driving directions. It contains some long sentences, and I am a neat freak, and would like to make sure that no line exceeds 50 characters. How do I accomplish that with PHP?

On large strings that need to be formatted according to some length specifications, use wordwrap() or chunk_split().

65. For printing out strings, there are echo, print and printf. Explain the differences.

echo is the most primitive of them, and just outputs the contents following the construct to the screen. print is also a construct (so parentheses are optional when calling it), but it returns TRUE on successful output and FALSE if it was unable to print out the string. However, you can pass multiple parameters to echo, like:

<?php echo 'Welcome ', 'to', ' ', 'globalguideline!'; ?>

and it will output the string "Welcome to globalguideline!" print does not take multiple parameters. It is also generally argued that echo is faster, but usually the speed advantage is negligible, and might not be there for future versions of PHP. printf is a function, not a construct, and allows such advantages as formatted output, but it’s the slowest way to print out data out of echo, print and printf.

66. Can we use include ("abc.php") two times in a php page "makeit.php"?

Yes.

67. How many ways we can retrieve the date in result set of mysql using php?

As individual objects so single record or as a set or arrays.

68. How can we create a database using PHP and mysql?

We can create MySQL database with the use of mysql_create_db($databaseName) to create a database.

69. How can we submit form without a submit button?

We can use a simple JavaScript code linked to an event trigger of any form field. In the JavaScript code, we can call the document.form.submit() function to submit the form. For example: <input type=button value="Save" onClick="document.form.submit()">

70. With a heredoc syntax, do I get variable substitution inside the heredoc contents?

Yes.

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71. What is the difference between characters 23 and x23?

The first one is octal 23, the second is hex 23.

72. How can we register the variables into a session?

session_register($session_var);

$_SESSION['var'] = 'value';

73. How come the code works, but does not for two-dimensional array of mine?

Any time you have an array with more than one dimension, complex parsing syntax is required. print "Contents: {$arr[1][2]}" would've worked.

74. What is the difference between the functions unlink and unset?

unlink() is a function for file system handling. It will simply delete the file in context.

unset() is a function for variable management. It will make a variable undefined.

75. How can we extract string abc.com from a string http://info@abc.com using regular expression of php?

We can use the preg_match() function with "/.*@(.*)$/" as
the regular expression pattern. For example:
preg_match("/.*@(.*)$/","http://info@abc.com",$data);
echo $data[1];

76. Would you initialize your strings with single quotes or double quotes?

Since the data inside the single-quoted string is not parsed for variable substitution, it's always a better idea speed-wise to initialize a string with single quotes, unless you specifically need variable substitution.

77. How can we submit a form without a submit button?

If you don't want to use the Submit button to submit a form, you can use normal hyper links to submit a form. But you need to use some JavaScript code in the URL of the link. For example:

<a href="javascript: document.myform.submit();">Submit Me</a>

78. What is the special meaning of __sleep and __wakeup?

__sleep returns the array of all the variables than need to be saved, while __wakeup retrieves them.

79. WHAT ARE THE DIFFERENT TYPES OF ERRORS IN PHP?

Here are three basic types of runtime errors in PHP:

1. Notices: These are trivial, non-critical errors that PHP encounters while executing a script - for example, accessing a variable that has not yet been defined. By default, such errors are not displayed to the user at all - although you can change this default behavior.

2. Warnings: These are more serious errors - for example, attempting to include() a file which does not exist. By default, these errors are displayed to the user, but they do not result in script termination.

3. Fatal errors: These are critical errors - for example, instantiating an object of a non-existent class, or calling a non-existent function. These errors cause the immediate termination of the script, and PHP's default behavior is to display them to the user when they take place.

Internally, these variations are represented by twelve different error types

80. How do you call a constructor for a parent class?

parent::constructor($value)

81. What are the differences between GET and POST methods in form submitting, give the case where we can use GET and we can use POST methods?

When we submit a form, which has the GET method it displays pair of name/value used in the form at the address bar of the browser preceded by url. Post method doesn't display these values.

82. What are the differences between DROP a table and TRUNCATE a table?

DROP TABLE table_name - This will delete the table and its data.

TRUNCATE TABLE table_name - This will delete the data of the table, but not the table definition.

83. Are objects passed by value or by reference?

Everything is passed by value.

84. How To Protect Special Characters in Query String?

If you want to include special characters like spaces in the query string, you need to protect them by applying the urlencode() translation function. The script below shows how to use urlencode():

<?php
print("<html>");
print("<p>Please click the links below"
." to submit comments about GlobalGuideLine.com:</p>");
$comment = 'I want to say: "It's a good site! :->"';
$comment = urlencode($comment);
print("<p>"
."<a href="processing_forms.php?name=Guest&comment=$comment">"
."It's an excellent site!</a></p>");
$comment = 'This visitor said: "It's an average site! :-("';
$comment = urlencode($comment);
print("<p>"
.'<a href="processing_forms.php?'.$comment.'">'
."It's an average site.</a></p>");
print("</html>");
?>

85. If the variable $a is equal to 5 and variable $b is equal to character a, what's the value of $$b?

100, it's a reference to existing variable.

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86. What is the purpose of the following files having extensions: frm, myd, and myi? What these files contain?

In MySQL, the default table type is MyISAM.
Each MyISAM table is stored on disk in three files. The files have names that begin with the table name and have an extension to indicate the file type.

The '.frm' file stores the table definition.
The data file has a '.MYD' (MYData) extension.
The index file has a '.MYI' (MYIndex) extension,

87. How do I find out the number of parameters passed into function9. ?

func_num_args() function returns the number of parameters passed in.

88. What is the difference between ereg_replace() and eregi_replace()?

eregi_replace() function is identical to ereg_replace() except that it ignores case distinction when matching alphabetic characters.

89. What is the functionality of the function strstr and stristr?

strstr() returns part of a given string from the first occurrence of a given substring to the end of the string. For example: strstr("user@example.com","@") will return "@example.com".
stristr() is idential to strstr() except that it is case insensitive.

90. How can we send mail using JavaScript?

No. There is no way to send emails directly using JavaScript.

But you can use JavaScript to execute a client side email program send the email using the "mailto" code. Here is an example:

function myfunction(form)
{
tdata=document.myform.tbox1.value;
location="mailto:mailid@domain.com?subject=...";
return true;
}

91. When are you supposed to use endif to end the conditional statement?

When the original if was followed by : and then the code block without braces.

92. WHAT IS THE FUNCTIONALITY OF THE FUNCTIONS STRSTR() AND STRISTR()?

string strstr ( string haystack, string needle ) returns part of haystack string from the first occurrence of needle to the end of haystack. This function is case-sensitive.

stristr() is idential to strstr() except that it is case insensitive.

93. How do you pass a variable by value?

Just like in C++, put an ampersand in front of it, like $a = &$b

94. How can we encrypt the username and password using PHP?

Answer1
You can encrypt a password with the following Mysql>SET PASSWORD=PASSWORD("Password");

Answer2
You can use the MySQL PASSWORD() function to encrypt username and password. For example,
INSERT into user (password, ...) VALUES (PASSWORD($password”)), ...);

95. How To Create a Table using PHP?

If you want to create a table, you can run the CREATE TABLE statement as shown in the following sample script:

<?php
include "mysql_connection.php";

$sql = "CREATE TABLE ggl_links ("
. " id INTEGER NOT NULL"
. ", url VARCHAR(80) NOT NULL"
. ", notes VARCHAR(1024)"
. ", counts INTEGER"
. ", time TIMESTAMP DEFAULT sysdate()"
. ")";
if (mysql_query($sql, $con)) {
print("Table ggl_links created.n");
} else {
print("Table creation failed.n");
}

mysql_close($con);
?>

Remember that mysql_query() returns TRUE/FALSE on CREATE statements. If you run this script, you will get something like this:
Table ggl_links created.

96. What are the different tables present in MySQL? Which type of table is generated when we are creating a table in the following syntax: create table employee(eno int(2),ename varchar(10))?

Total 5 types of tables we can create
1. MyISAM
2. Heap
3. Merge
4. INNO DB
5. ISAM
MyISAM is the default storage engine as of MySQL 3.23. When you fire the above create query MySQL will create a MyISAM table.

97. Would I use print "$a dollars" or "{$a} dollars" to print out the amount of dollars in this example?

In this example it wouldn't matter, since the variable is all by itself, but if you were to print something like "{$a},000,000 mln dollars", then you definitely need to use the braces.

98. I am trying to assign a variable the value of 0123, but it keeps coming up with a different number, what is the problem?

PHP Interpreter treats numbers beginning with 0 as octal. Look at the similar PHP interview questions for more numeric problems.

99. How can I execute a PHP script using command line?

Just run the PHP CLI (Command Line Interface) program and provide the PHP script file name as the command line argument. For example, "php myScript.php", assuming "php" is the command to invoke the CLI program.
Be aware that if your PHP script was written for the Web CGI interface, it may not execute properly in command line environment.

100. What is the difference between mysql_fetch_object and mysql_fetch_array?

MySQL fetch object will collect first single matching record where mysql_fetch_array will collect all matching records from the table in an array

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101. How To Get the Uploaded File Information in the Receiving Script?

Once the Web server received the uploaded file, it will call the PHP script specified in the form action attribute to process them. This receiving PHP script can get the uploaded file information through the predefined array called $_FILES. Uploaded file information is organized in $_FILES as a two-dimensional array as:

* $_FILES[$fieldName]['name'] - The Original file name on the browser system.
* $_FILES[$fieldName]['type'] - The file type determined by the browser.
* $_FILES[$fieldName]['size'] - The Number of bytes of the file content.
* $_FILES[$fieldName]['tmp_name'] - The temporary filename of the file in which the uploaded file was stored on the server.
* $_FILES[$fieldName]['error'] - The error code associated with this file upload.

The $fieldName is the name used in the <INPUT TYPE=FILE, NAME=fieldName>.

102. What is meant by urlencode and urldecode?

Anwser 1:
urlencode() returns the URL encoded version of the given string. URL coding converts special characters into % signs followed by two hex digits. For example: urlencode("10.00%") will return "10%2E00%25". URL encoded strings are safe to be used as part of URLs.
urldecode() returns the URL decoded version of the given string.

Anwser 2:
string urlencode(str) - Returns the URL encoded version of the input string. String values to be used in URL query string need to be URL encoded. In the URL encoded version:

Alphanumeric characters are maintained as is.
Space characters are converted to "+" characters.
Other non-alphanumeric characters are converted "%" followed by two hex digits representing the converted character.

string urldecode(str) - Returns the original string of the input URL encoded string.

For example:

$discount ="10.00%";
$url = "http://domain.com/submit.php?disc=".urlencode($discount);
echo $url;

You will get "http://domain.com/submit.php?disc=10%2E00%25".

103. What are the differences between require and include, include_once?

Anwser 1:
require_once() and include_once() are both the functions to include and evaluate the specified file only once. If the specified file is included previous to the present call occurrence, it will not be done again.

But require() and include() will do it as many times they are asked to do.

Anwser 2:
The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. The major difference between include() and require() is that in failure include() produces a warning message whereas require() produces a fatal errors.

Anwser 3:
All three are used to an include file into the current page.
If the file is not present, require(), calls a fatal error, while in include() does not.
The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. It des not call a fatal error if file not exists. require_once() does the same as include_once(), but it calls a fatal error if file not exists.

Anwser 4:
File will not be included more than once. If we want to include a file once only and further calling of the file will be ignored.

104. How To Write the FORM Tag Correctly for Uploading Files?

When users clicks the submit button, files specified in the <INPUT TYPE=FILE...> will be transferred from the browser to the Web server. This transferring (uploading) process is controlled by a properly written <FORM...> tag as:

<FORM ACTION=receiving.php METHOD=post ENCTYPE=multipart/form-data>

Note that you must specify METHOD as "post" and ENCTYPE as "multipart/form-data" in order for the uploading process to work. The following PHP code, called logo_upload.php, shows you a complete FORM tag for file uploading:

<?php
print("<html><form action=processing_uploaded_files.php"
." method=post enctype=multipart/form-data>n");
print("Please submit an image file a Web site logo for"
." globalguideline.com:<br>n");
print("<input type=file name=globalguideline_logo><br>n");
print("<input type=submit>n");
print("</form></html>n");
?>

105. How do you define a constant in PHP?

Via define() directive, like define ("MYCONSTANT", 100);

106. What does a special set of tags do in PHP?

What does a special set of tags <?= and ?> do in PHP?
The output is displayed directly to the browser.

107. What Is a Persistent Cookie in PHP?

A persistent cookie is a cookie which is stored in a cookie file permanently on the browser's computer. By default, cookies are created as temporary cookies which stored only in the browser's memory. When the browser is closed, temporary cookies will be erased. You should decide when to use temporary cookies and when to use persistent cookies based on their differences:

* Temporary cookies can not be used for tracking long-term information.
* Persistent cookies can be used for tracking long-term information.
* Temporary cookies are safer because no programs other than the browser can access them.
* Persistent cookies are less secure because users can open cookie files see the cookie values.

108. What is the difference between $message and $$message?

Anwser 1:
$message is a simple variable whereas $$message is a reference variable. Example:
$user = 'bob'

is equivalent to

$holder = 'user';
$$holder = 'bob';


Anwser 2:
They are both variables. But $message is a variable with a fixed name. $$message is a variable who's name is stored in $message. For example, if $message contains "var", $$message is the same as $var.

109. How can we repair a MySQL table?

The syntex for repairing a mysql table is:

REPAIR TABLE tablename
REPAIR TABLE tablename QUICK
REPAIR TABLE tablename EXTENDED

This command will repair the table specified.
If QUICK is given, MySQL will do a repair of only the index tree.
If EXTENDED is given, it will create index row by row.

110. How can we know the number of days between two given dates using PHP?

Simple arithmetic:

$date1 = date('Y-m-d');
$date2 = '2006-07-01';
$days = (strtotime() - strtotime()) / (60 * 60 * 24);
echo "Number of days since '2006-07-01': $days";

111. What is meant by PEAR in php?

Answer1:
PEAR is the next revolution in PHP. This repository is bringing higher level programming to PHP. PEAR is a framework and distribution system for reusable PHP components. It eases installation by bringing an automated wizard, and packing the strength and experience of PHP users into a nicely organised OOP library. PEAR also provides a command-line interface that can be used to automatically install "packages"

Answer2:
PEAR is short for "PHP Extension and Application Repository" and is pronounced just like the fruit. The purpose of PEAR is to provide:
A structured library of open-sourced code for PHP users
A system for code distribution and package maintenance
A standard style for code written in PHP
The PHP Foundation Classes (PFC),
The PHP Extension Community Library (PECL),
A web site, mailing lists and download mirrors to support the PHP/PEAR community
PEAR is a community-driven project with the PEAR Group as the governing body. The project has been founded by Stig S. Bakken in 1999 and quite a lot of people have joined the project since then.

112. What Is a Session in PHP?

A session is a logical object created by the PHP engine to allow you to preserve data across subsequent HTTP requests.

There is only one session object available to your PHP scripts at any time. Data saved to the session by a script can be retrieved by the same script or another script when requested from the same visitor.

Sessions are commonly used to store temporary data to allow multiple PHP pages to offer a complete functional transaction for the same visitor.

113. What is PHP?

The PHP Hypertext Preprocessor is a programming language that allows web developers to create dynamic content that interacts with databases. PHP is basically used for developing web based software applications.

114. How To Replace a Substring in a Given String in PHP?

If you know the position of a substring in a given string, you can replace that substring by another string by using the substr_replace() function. Here is a PHP script on how to use substr_replace():

<?php
$string = "Warning: System will shutdown in NN minutes!";
$pos = strpos($string, "NN");
print(substr_replace($string, "15", $pos, 2)." ");
sleep(10*60);
print(substr_replace($string, "5", $pos, 2)." ");
?>

This script will print:

Warning: System will shutdown in 15 minutes!
(10 minutes later)
Warning: System will shutdown in 5 minutes!

Like substr(), substr_replace() can take negative starting position counted from the end of the string.

115. How To Take a Substring from a Given String in PHP?

If you know the position of a substring in a given string, you can take the substring out by the substr() function. Here is a PHP script on how to use substr():

<?php
$string = "beginning";
print("Position counted from left: ".substr($string,0,5)." ");
print("Position counted form right: ".substr($string,-7,3)." ");
?>

This script will print:

Position counted from left: begin
Position counted form right: gin

substr() can take negative starting position counted from the end of the string.

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116. What Is the Best Way to Test the strpos() Return Value in PHP?

Because strpos() could two types of values, Integer and Boolean, you need to be careful about testing the return value. The best way is to use the "Identical(===)" operator. Do not use the "Equal(==)" operator, because it does not differentiate "0" and "false". Check out this PHP script on how to use strpos():

<?php
$haystack = "needle234953413434516504381640386488129";
$pos = strpos($haystack, "needle");
if ($pos==false) {
print("Not found based (==) test ");
} else {
print("Found based (==) test ");
}
if ($pos===false) {
print("Not found based (===) test ");
} else {
print("Found based (===) test ");
}
?>

This script will print:

Not found based (==) test
Found based (===) test

Of course, (===) test is correct.

117. How to Find a Substring from a Given String in PHP?

To find a substring in a given string, you can use the strpos() function. If you call strpos($haystack, $needle), it will try to find the position of the first occurrence of the $needle string in the $haystack string. If found, it will return a non-negative integer represents the position of $needle. Othewise, it will return a Boolean false. Here is a PHP script example of strpos():

<?php
$haystack1 = "2349534134345globalguideline16504381640386488129";
$haystack2 = "globalguideline234953413434516504381640386488129";
$haystack3 = "guideline234953413434516504381640386488129ggl";
$pos1 = strpos($haystack1, "globalguideline");
$pos2 = strpos($haystack2, "globalguideline");
$pos3 = strpos($haystack3, "globalguideline");
print("pos1 = ($pos1); type is " . gettype($pos1) . " ");
print("pos2 = ($pos2); type is " . gettype($pos2) . " ");
print("pos3 = ($pos3); type is " . gettype($pos3) . " ");
?>

This script will print:

pos1 = (13); type is integer
pos2 = (0); type is integer
pos3 = (); type is boolean

"pos3" shows strpos() can return a Boolean value

118. How To Remove Leading and Trailing Spaces from User Input Values in PHP?

If you are taking input values from users with a Web form, users may enter extra spaces at the beginning and/or the end of the input values. You should always use the trim() function to remove those extra spaces as shown in this PHP script:

<?php
$name = $_REQUEST("name");
$name = trim($name);
# $name is ready to be used...
?>

119. How To Remove the New Line Character from the End of a Text Line in PHP?

If you are using fgets() to read a line from a text file, you may want to use the chop() function to remove the new line character from the end of the line as shown in this PHP script:

<?php
$handle = fopen("/tmp/inputfile.txt", "r");
while ($line=fgets()) {
$line = chop($line);
# process $line here...
}
fclose($handle);
?>

120. How To Remove White Spaces from the Beginning and/or the End of a String in PHP?

There are 4 PHP functions you can use remove white space characters from the beginning and/or the end of a string:

► trim() - Remove white space characters from the beginning and the end of a string.
► ltrim() - Remove white space characters from the beginning of a string.
► rtrim() - Remove white space characters from the end of a string.
► chop() - Same as rtrim().

White space characters are defined as:

► " " (ASCII 32 (0x20)), an ordinary space.
► " " (ASCII 9 (0x09)), a tab.
► " " (ASCII 10 (0x0A)), a new line (line feed).
► " " (ASCII 13 (0x0D)), a carriage return.
► "" (ASCII 0 (0x00)), the NULL-byte.
► "x0B" (ASCII 11 (0x0B)), a vertical tab.
Here is a PHP script example of trimming strings:
<?php
$text = " Hello world! ";
$leftTrimmed = ltrim($text);
$rightTrimmed = rtrim($text);
$bothTrimmed = trim($text);
print("leftTrimmed = ($leftTrimmed) ");
print("rightTrimmed = ($rightTrimmed) ");
print("bothTrimmed = ($bothTrimmed) ");
?>

This script will print:

leftTrimmed = (Hello world!              )
rightTrimmed = (         Hello world!)
bothTrimmed = (Hello world!)

121. How To Get the Number of Characters in a String?

You can use the "strlen()" function to get the number of characters in a string. Here is a PHP script example of strlen():

<?php
print(strlen('It's Friday!'));
?>

This script will print:

12

122. How To Convert Strings to Numbers in PHP?

In a numeric context, PHP will automatically convert any string to a numeric value. Strings will be converted into two types of numeric values, double floating number and integer, based on the following rules:

► The value is given by the initial portion of the string. If the string starts with valid numeric data, this will be the value used. Otherwise, the value will be 0 (zero).
► If the valid numeric data contains '.', 'e', or 'E', it will be converted to a double floating number. Otherwise, it will be converted to an integer.

123. How To Convert Numbers to Strings in PHP?

In a string context, PHP will automatically convert any numeric value to a string. Here is a PHP script examples:

<?php
print(-1.3e3);
print(" ");
print(strlen(-1.3e3));
print(" ");
print("Price = $" . 99.99 . " ");
print(1 . " + " . 2 . " = " . 1+2 . " ");
print(1 . " + " . 2 . " = " . (1+2) . " ");
print(1 . " + " . 2 . " = 3 ");
print(" ");
?>

This script will print:

-1300
5
Price = $99.99
3
1 + 2 = 3
1 + 2 = 3

The print() function requires a string, so numeric value -1.3e3 is automatically converted to a string "-1300". The concatenation operator (.) also requires a string, so numeric value 99.99 is automatically converted to a string "99.99". Expression (1 . " + " . 2 . " = " . 1+2 . " ") is a little bit interesting. The result is "3 " because concatenation operations and addition operation are carried out from left to right. So when the addition operation is reached, we have "1 + 2 = 1"+2, which will cause the string to be converted to a value 1.

124. How To Compare Two Strings with Comparison Operators in PHP?

PHP supports 3 string comparison operators, <, ==, and >, that generates Boolean values. Those operators use ASCII values of characters from both strings to determine the comparison results. Here is a PHP script on how to use comparison operators:

<?php
$a = "PHP is a scripting language.";
$b = "PHP is a general-purpose language.";
if ($a > $b) {
print('$a > $b is true.'." ");
} else {
print('$a > $b is false.'." ");
}
if ($a == $b) {
print('$a == $b is true.'." ");
} else {
print('$a == $b is false.'." ");
}
if ($a < $b) {
print('$a < $b is true.'." ");
} else {
print('$a < $b is false.'." ");
}
?>

This script will print:

$a > $b is true.
$a == $b is false.
$a < $b is false.

125. How To Concatenate Two Strings Together in PHP?

You can use the string concatenation operator (.) to join two strings into one. Here is a PHP script example of string concatenation:

<?php
echo 'Hello ' . "world! ";
?>

This script will print:

Hello world!

126. How To Assigning a New Character in a String using PHP?

The string element expression, $string{index}, can also be used at the left side of an assignment statement. This allows you to assign a new character to any position in a string. Here is a PHP script example:

<?php
$string = 'It's Friday?';
echo "$string ";
$string{11} = '!';
echo "$string ";
?>

This script will print:

It's Friday?
It's Friday!

127. How To Access a Specific Character in a String using PHP?

Any character in a string can be accessed by a special string element expression:

► $string{index} - The index is the position of the character counted from left and starting from 0.

Here is a PHP script example:

<?php
$string = 'It's Friday!';
echo "The first character is $string{0} ";
echo "The first character is {$string{0}} ";
?>

This script will print:

The first character is It's Friday!{0}
The first character is I

128. How Many Ways to Include Array Elements in Double-Quoted Strings using PHP?

There are 2 formats to include array elements in double-quoted strings in PHP:

► "part 1 $array[key] part 2" - This is called simple format. In this format, you can not specify the element key in quotes.
► "part 1 {$array['key']} part 2" - This is called complex format. In this format, the array element expression is specified in the same way as in a normal statement.

Here is a PHP script example of different ways to include variables in double-quoted strings:

<?php
$fruits = array('strawberry' => 'red', 'banana' => 'yellow');
echo "A banana is $fruits[banana]. ";
echo "A banana is {$fruits['banana']}. ";
?>

This script will print:

A banana is yellow.
A banana is yellow.

"A banana is $fruits['banana']. " will give you a syntax error.

129. How Many Ways to Include Variables in Double-Quoted Strings in PHP?

There are 3 formats to include variables in double-quoted strings:

► "part 1 $variable part 2" - This is the simplest format to include a variable in a string. The variable name starts with the dollar sign and ends at the first character that can not be used in variable name. Space is good character to end a variable name.
► "part 1${variable}part 2" - This format helps you to clearly end the variable name. The variable name starts at dollar sign before the open brace (${) and ends at the close brace (}).
► "part 1{$variable}part 2" - This format is also called complex format. You use this format to specify any complex variable expression in the same way as in a normal statement. The variable expression starts at ({$) followed by a variable name and ends at (}).

Here is a PHP script example of different ways to include variables in double-quoted strings:

<?php
$beer = 'Heineken';
echo "$beer's taste is great. ";
echo "He drank some ${beer}s and water. ";
echo "She drank some {$beer}s and water. ";
?>

This script will print:

Heineken's taste is great.
He drank some Heinekens and water.
She drank some Heinekens and water.

130. How To Include Variables in Double-Quoted Strings in PHP?

Variables included in double-quoted strings will be interpolated. Their values will be concatenated into the enclosing strings. For example, two statements in the following PHP script will print out the same string:

<?php
$variable = "and";
echo "part 1 $variable part 2 ";
echo "part 1 ".$variable." part 2 ";
?>

This script will print:

part 1 and part 2
part 1 and part 2

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131. How Many Escape Sequences Are Recognized in Double-Quoted Strings in PHP?

There are 12 escape sequences you can use in double-quoted strings:

► - Represents the back slash character.
► " - Represents the double quote character.
► $ - Represents the dollar sign.
► - Represents the new line character (ASCII code 10).
► - Represents the carriage return character (ASCII code 13).
► - Represents the tab character (ASCII code 9).
► { - Represents the open brace character.
► } - Represents the close brace character.
► [ - Represents the open bracket character.
► ] - Represents the close bracket character.
► nn - Represents a character as an octal value.
► xnn - Represents a character as a hex value.

132. What Are the Special Characters You Need to Escape in Double-Quoted Stings?

There are two special characters you need to escape in a double-quote string: the double quote (") and the back slash (). Here is a PHP script example of double-quoted strings:

<?php
echo "Hello world!";
echo "Tom said: "Who's there?"";
echo " represents an operator.";
?>

This script will print:

Hello world!Tom said: "Who's there?" represents an operator.

133. Can You Specify the "new line" Character in Single-Quoted Strings?

You can not specify the "new line" character in a single-quoted string. If you don't believe, try this script:

<?php
echo ' will not work in single quoted strings.';
?>

This script will print:

will not work in single quoted strings.

How Many Escape Sequences Are Recognized in Single-Quoted Strings?

There are 2 escape sequences you can use in single-quoted strings:

► - Represents the back slash character.
► ' - Represents the single quote character.

134. What Are the Special Characters You Need to Escape in Single-Quoted Stings?

There are two special characters you need to escape in a single-quote string: the single quote (') and the back slash (). Here is a PHP script example of single-quoted strings:

<?php
echo 'Hello world!';
echo 'It's Friday!';
echo ' represents an operator.';
?>

This script will print:

Hello world!It's Friday! represents an operator.

135. How To Run a PHP Script?

A standard alone PHP script can be executed directly with the PHP Command Line Interface (CLI). Write the following script in a file called hello.php:

<?php echo "Hello world!"; ?>

This script can be executed by CLI interface like this:

phpphp hello.php

You should see the "Hello world!" message printed on your screen.

136. Where Are PHP Configuration Settings Stored?

PHP stores configuration settings in a file called php.ini in PHP home directory. You can open it with any text editor to your settings.

137. How To Download and Install PHP for Windows?

The best way to download and install PHP on Windows systems is to:

► Go to http://www.php.net, which is the official Web site for PHP.
► Download PHP binary version for Windows in ZIP format.
► Unzip the downloaded file into a directory.

You are done. No need to run any install program.

138. How To Check Your PHP Installation?

PHP provides two execution interfaces: Command Line Interface (CLI) and Common Gateway Interface (CGI). If PHP is installed in the php directory on your system, you can try this to check your installation:

* Run "phpphp -v" command to check the Command Line Interface (CLI).
* Run "phpphp-cgi -v" command to check the Common Gateway Interface (CGI).

If you see PHP printing the version information on your screen for both commands, your installation is ok. Open a command window and run the commands below:

C:>phpphp -v
PHP 5.2.2 (cli) (built: May 2 2007 19:18:26)
Copyright (c) 1997-2007 The PHP Group
Zend Engine v2.2.0 Copyright (c) 1998-2007 Zend Technologies

C:>phpphp-cgi -v
PHP 5.2.2 (cgi-fcgi) (built: May 2 2007 19:18:25)
Copyright (c) 1997-2007 The PHP Group
Zend Engine v2.2.0 Copyright (c) 1998-2007 Zend Technologies

139. How To Download and Install PHP on Windows?

PHP is one of the most popular languages to develop dynamic Web pages. It supports all major database servers, including: MySQL, MS SQL Server, Oracle, mSQL, Sybase, etc.

If you are developing a Web application that uses PHP and needs to access MS SQL Server, you should go download and install PHP to your local machine to practice PHP and SQL Server connection. The best way to download and install PHP on Windows systems is to:

* Go to http://www.php.net, which is the official Web site for PHP.
* Click the Downloads menu link. You will see the PHP download page.
* Go to the "Windows Binaries" section, and click "PHP 5.2.3 zip package" link to download PHP binary version for Windows in ZIP format.
* Save the downloaded file, php-5.2.3-Win32.zip with 9,847,499 bytes, in C:Temp directory.
* Unzip the downloaded file into directory C:php.

You are done. No need to run any installation program.