Most Important 100+ PHP Interview Question and Answer

<?php 

 $a=true ;

 $b=1;

 // Below condition returns true and prints a and b are equal

 if($a==$b){

  echo "a and b are equal";

 }

 else{

  echo "a and b are not equal";

 }

 //Below condition returns false and prints a and b are not equal because $a and $b are of  different data types.

 if($a===$b){

  echo "a and b are equal";

 }

 else{

  echo "a and b are not equal";

 }

?>

<?php 

 // starting a session

 session_start();

 // Creating a session

 $_SESSION['user_info'] = ['user_id' =>1,

 'first_name' =>

 'Ramesh', 'last_name' =>

 'Kumar', 'status' =>

 'active'];

 // checking session

 if (isset($_SESSION['user_info']))

    {

    echo "logged In";

    }

 // un setting remove a value from session

 unset($_SESSION['user_info']['first_name']);

 // destroying complete session

 session_destroy();

?>

<?php

 // Starting session

  session_start();

 // Use of session_register() is deprecated

  $username = "PhpScots";

  session_register("username");

 // Use of $_SESSION is preferred

  $_SESSION["username"] = "PhpScots";

?>

<?php

 // server should keep session data for AT LEAST 1 hour

 ini_set('session.gc_maxlifetime', 3600);

 // each client should remember their session id for EXACTLY 1 hour

 session_set_cookie_params(3600);

?>

<?php

 class Foo {

 private $name;

 private $link;

 public function __construct($name) {

     $this->name = $name;

 }

 public function setLink(Foo $link){

     $this->link = $link;

 }

 public function __destruct() {

     echo 'Destroying: ', $this->name, PHP_EOL;

 }

 }

?>

<?php

 function sendEmail (Email $email)

 {

   $email->send();

 }

?>

<?php 

 $email = ‘abc@xyz.com’;

 $hostname = strstr($email, ‘@’);

 echo $hostname;

 output: @xyz.com

 stristr() does the same thing in Case-insensitive manner

?>

<?php

 // initializing an array in PHP

 $array=['a','b','c'];

 // Outputs 3 

 echo count($array);

?>

<?php 

 $email = ‘abc@xyz.com’;

 $hostname = strstr($email, ‘@’);

 echo $hostname;

 output: @xyz.com

 stristr() does the same thing in Case-insensitive manner

?>

<?php

 function foo() 

 {

 return  func_get_args();

 }

 echo foo(1,5,7,3);//output 4;

 echo foo(a,b);//output 2;

 echo foo();//output 0;

?>

<?php

 # define namespace and class in namespace

 namespace Modules\Admin\;

 class CityController {

 }

 # include the class using namesapce

 use Modules\Admin\CityController ;

?>

<?php

 header("Content-type: image/png"); 

 $string = $_GET['text'];

 $im = imagecreatefrompng("images/button1.png");

 $mongo = imagecolorallocate($im, 220, 210, 60);

 $px = (imagesx($im) - 7.5 * strlen($string)) / 2;

 imagestring($im, 3, $px, 9, $string, $mongo);

 imagepng($im);

 imagedestroy($im);

?>

<?php

 $age = array("Peter"=>"37", "Ben"=>"27", "Joe"=>"43");

 asort($age);

?>

<?php

 $str = "10"; // $str is now string

 $bool = (boolean) $str; // $bool is now boolean

?>

<?php

 $val = 5; // $val is now number

 $val = "500" //$val is now string

?>

<?php

 $DBconnection = mysqli_connect("localhost","username","password","dbname");

 2

 // Check for valid connection 

 3

 if (mysqli_connect_errno())

 4

 {

 5

 echo "Unable to connect with MySQL: " . mysqli_connect_error();

 6

 }

?>

<?php

 if (imagetypes() &IMG_BMP) {

     echo "BMP extension Support is enabled";

 }

?>

<?php

 //Remove all tags from the text 

 echo strip_tags("<b>PHP</b> is a popular <em>scripting</em> language");

 //Remove all tags excluding <b> tag 

 echo strip_tags("<b>PHP</b> is a popular <em>scripting</em> language","<b>");

?>

<?php

 define("PI",3.14);

?>

<?php

 //Loop will iterate for 5 times 

 for ($n = 0; $n <= 5; $n++) {

 echo "The number is: $n <br>";

 4

}

?>

<?php

 $n = 10;

 if ($n === "10")

 echo "n is equal to 10";

 else

 echo "n is not equal to 10"; //This will print

?>

<?php

 $str= “hello”;

 Echo soundex($str);

?>

<?php

 $str= “hello”;

 echo metaphone(“world”);

?>

<?php

 $var1 = ‘Variable 1’

 $$var1= ‘variable2’

 This can be interpreted as $ Variable 1=‘variable2’;

 For me to print value of both variables, I will write

 $var1 $($var1)

?>

<?php

 $Message = "YOU";

 $you= "Me";

 echo $message //Output:- you

 echo $$message //output :-Me

?>

<?php

 function foo() 

 {

    return  func_get_args();

 }

 echo foo(1,5,7,3);//output 4;

 echo foo(a,b);//output 2;

 echo foo();//output 0;

?>

<?php

 function getTrueIpAddr(){

  if (!empty($_SERVER['HTTP_CLIENT_IP']))   //check ip from share internet

     {

       $ip=$_SERVER['HTTP_CLIENT_IP'];

     }

  elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR']))   //to check ip is pass from proxy

   {

       $ip=$_SERVER['HTTP_X_FORWARDED_FOR'];

   }

     else

   {

       $ip=$_SERVER['REMOTE_ADDR'];

   }

     return $ip;

 }

?>