PHP stristr() Function

PHP stristr() Function

The stristr() function in PHP finds the first occurrence of a string and returns the matched substring. It is a case-insensitive function.

Syntax

stristr ( string $haystack , mixed $needle [, bool $before_needle ] )

Parameter

haystack(required)- This parameter represents the input string.

needle(required)- This parameter signifies the string to search for. If it is a number, it will search for the character matching the ASCII value of the number.

before_needle(optional)- This parameter takes a boolean and its value default is "false". If it is set to "true", it returns the part of the string before the first occurrence of the search parameter.

Return

This function returns all of haystack starting from and including the first occurrence of needle to the end. If the needle is not found, it returns FALSE.

Example 1

<?php
  // initializing the string value
  $email = 'abc@gmail.com';
  echo "Original string: ".$email;
  echo "\nAfter the stristr() function...\n";
  //searching for the first occurrence of "e" inside string "$email". 
  echo "New String: ".stristr($email, 'b'); // bc@gmail.com
?> 

Output

Original string: abc@gmail.com
After the stristr() function...
New String: bc@gmail.com 

Example 2

<?php
   // initializing the string value
   $email = 'abc@gmail.com';
   echo "Original string: ".$email;
   echo "\nAfter the stristr() function...\n";
   //searching for the first occurrence of "e" inside string "$email". 
   echo "Output: ".stristr($email, 97); // 97 = lowercase a
   // output abc@gmail.com
 ?> 

Output

Original string: abc@gmail.com
After the stristr() function...
abc@gmail.com 

Example 3

<?php
   // initializing the string value
   $email = 'abc@gmail.com';
   echo "Original string: ".$email;
   echo "\nAfter the stristr() function...\n";
   //searching for the first occurrence of "e" inside string "$email". 
   echo "Output: ".stristr($email, 'b', true); // set true will return the part of the string before b.
   // output a
 ?> 

Output

Original string: abc@gmail.com
After the stristr() function...
Output: a 

Example 4

<?php
   // initializing the string value
   $str = "Hello PHP";
   echo "Original string: ".$str;
   if(stristr($str, 'world') === FALSE) {
       echo"\n";
     echo 'Sorry! "world" not found in string'; 
   }
 ?> 

Output

Original string: Hello PHP
Sorry!"world" not found in string