Behavioral Jnr PHP/Codeigniter Developer Interview Questions & Answers:

1. Tell me what Is a Persistent Cookie?

The type of cookie which is stored permanently on the browser. A persistent cookie can be used for tracking long-term information.

2. Tell me do you use Composer? If yes, what benefits have you found in it?

Using Composer is a tool for dependency management. The candidate can declare the libraries your product relies on and Composer will manage the installation and updating of the libraries. The benefit is a consistent way of managing the libraries depended on so less time is spent managing the libraries.

3. Tell me does PHP support multiple inheritance?

No. But class can implement multiple interfaces. Multiple inheritance is partially possible using traits.

4. Do you know what is Polymorphism?

It is the basic principle of OOP. You can define base class (may be abstract) Animals and it can then be extended by other classes like Dog, Cat and take part of the behaviour from the parent class.

5. Tell us can you send an Ajax request to another domain?

It is not possible to send an Ajax request if the protocol or host are different. This is called CORS and is checked by the browser.

6. Explain me what's the difference between unset() and unlink()?

unset() sets a variable to “undefined” while unlink() deletes a file we pass to it from the file system.

7. Tell me will comparison of string "10" and integer 11 work in PHP?

Yes, it will, because PHP is not a typed language and it will try to convert variable types before comparison.

8. Tell us can you extend a Final defined class?

No, you cannot extend a Final defined class. A Final class or method declaration prevents child class or method overriding.

9. Explain me what is the difference between the functions unlink and unset?

Unlink() deletes the given file from the file system. Where unset() makes a variable undefined from memory.

10. Tell me what is Memcache?

Technology that caches objects in memory and the application can get to them really fast. It is the basis in scaling larger PHP application.