PHP interview questions and answers

 1.What is PHP?

         PHP is a server side scripting language commonly used for web applications. PHP has many frameworks and cms for creating websites.Even a non technical person can cretae sites using its CMS.WordPress,osCommerce are the famus CMS of php.It is also an object oriented programming language like java,C-sharp etc.It is very eazy for learning

  2.What is the use of "echo" in php?
       
        It is used to print a data in the webpage, Example: <?php echo 'Car insurance'; ?> , The following code print the text in the webpage

  3.How to include a file to a php page?

        We can include a file using "include() " or "require()" function with file path as its parameter.

  4.What's the difference between include and require?

      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.

  5.require_once(), require(), include().What is difference between them?

       require() includes and evaluates a specific file, while require_once() does that only if it has not been included before (on the same page). So, require_once() is recommended to use when you want to include a file where you have a lot of functions for example. This way you make sure you don't include the file more times and you will not get the "function re-declared" error.

  6.Differences between GET and POST methods ?

   We can send 1024 bytes using GET method but POST method can transfer large amount of data and POST is the secure method than GET method .

  7.How to declare an array in php?

     Eg : var $arr = array('apple', 'grape', 'lemon');

  8.What is the use of 'print' in php?
   
     This is not actually a real function, It is a language construct. So you can use with out parentheses with its argument list.
Example print('PHP Interview questions');
print 'Job Interview ');

  9.What is use of in_array() function in php ?
   
    in_array used to checks if a value exists in an array

  10.What is use of count() function in php ?

    count() is used to count all elements in an array, or something in an object