PHP Manual: Find the position of the first occurrence of a case-insensitive substring in a string

Description

intfalse stripos(string $haystack, string $needle, int $offset = 0)

Find the numeric position of the first occurrence of needle in the haystack string.

Unlike the strpos, stripos is case-insensitive.

Parameters

haystack

The string to search in.

needle

The string to search for.

Prior to PHP 8.0.0, if needle is not a string, it is converted to an integer and applied as the ordinal value of a character. This behavior is deprecated as of PHP 7.3.0, and relying on it is highly discouraged. Depending on the intended behavior, the needle should either be explicitly cast to string, or an explicit call to chr should be performed.

offset

If specified, search will start this number of characters counted from the beginning of the string. If the offset is negative, the search will start this number of characters counted from the end of the string.

Return Values

Returns the position of where the needle exists relative to the beginning of the haystack string (independent of offset). Also note that string positions start at 0, and not 1.

Returns false if the needle was not found.

Warning

This function may return Boolean false, but may also return a non-Boolean value which evaluates to false. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

Changelog

Version	Description
8.2.0	Case folding no longer depends on the locale set with setlocale. Only ASCII case folding will be done. Non-ASCII bytes will be compared by their byte value.
8.0.0	`needle` now accepts an empty string.
8.0.0	Passing an int as `needle` is no longer supported.
7.3.0	Passing an int as `needle` has been deprecated.
7.1.0	Support for negative `offset`s has been added.

Examples

Example #1 stripos examples

<?php
$findme    = 'a';
$mystring1 = 'xyz';
$mystring2 = 'ABC';

$pos1 = stripos($mystring1, $findme);
$pos2 = stripos($mystring2, $findme);

// Nope, 'a' is certainly not in 'xyz'
if ($pos1 === false) {
    echo "The string '$findme' was not found in the string '$mystring1'";
}

// Note our use of ===.  Simply == would not work as expected
// because the position of 'a' is the 0th (first) character.
if ($pos2 !== false) {
    echo "We found '$findme' in '$mystring2' at position $pos2";
}
?>

Notes

Note: This function is binary-safe.

stripos