PHP mb_stripos() Function

The mb_stripos() function is an inbuilt case-insensitive function that finds the first occurrence of a substring in the string.

Syntax:

int|false mb_stripos( 
    string $haystack, 
    string $needle, 
    int $offset , 
    ?string $encoding
);

Parameters: This function accepts 4 parameters that are described below.

• $haystack: This parameter is the main string parameter where we check the string.
• $needle: This parameter is searching string parameter in the main string.
• $offset: This parameter is an optional parameter. It is used for defining where you are to start searching string in the $haystack parameter.
• $encoding: This parameter is also optional. It is used for defining an encoding by using the mb_internal_encoding() function.

Return Values: This function returns the integer of the first occurrence of $needle in the $haystack parameter. If $needle is not found in the $haystack parameter, it will return “false”.

Program 1: The following code demonstrates the mb_stripos() function.

<?php
  
$string = "Hello World";
$sub = "WORLD";

$result = mb_stripos($string, $sub);

if ($result !== false) {
    echo "Substring '$sub' found in '$string'";
} else {
    echo "Substring '$sub' not found in '$string'";
}
?>

Substring 'WORLD' found in 'Hello World'

Program 2: The following program demonstrates the mb_stripos() function.

<?php

$string = "This is a test string";
$substring = "ing";

$position = mb_stripos($string, $substring);

// Output the position
echo $position;

?>

18

Program 3: The following program demonstrates the mb_stripos() function

<?php
  
$string = "She sells seashells by the seashore.";
$substring = "S";

$position = 0;
$occurrences = 0;

while (($position = mb_stripos($string, $substring, 
                            $position)) !== false) {
    $occurrences++;
    $position = $position + mb_strlen($substring);
}

echo "The substring '$substring' was "+
     "found $occurrences times in the string.";
?>

The substring 'S' was found 8 times in the string.

Reference: https://www.php.net/manual/en/function.mb-stripos.php