PHP stripos() Function: Case‑Insensitive Search for Substring Position

The stripos() function in PHP finds the position of the first occurrence of a substring within a string without regard to case.

Parameters: $haystack – the string to search in. $needle – the substring to look for; if not a string it is converted to an integer. $offset (optional) – the position in $haystack to start searching from; the returned index is still relative to the start of the string.

Return value: The numeric position of $needle in $haystack (starting at 0) or FALSE if the needle is not found.

Example:

<?php
$findme = 'a';
$mystring1 = 'xyz';
$mystring2 = 'ABC';
$pos1 = stripos($mystring1, $findme);
$pos2 = stripos($mystring2, $findme);
if ($pos1 === false) {
    echo "The string '$findme' was not found in the string '$mystring1'";
}
if ($pos2 !== false) {
    echo "We found '$findme' in '$mystring2' at position $pos2";
}
?>

The script outputs a message indicating that the character ‘a’ was not found in “xyz”, and that it was found at position 0 in “ABC”.