PHP 8 reference · String Functions

PHP stripos() Function

Find the position of the first occurrence of a substring, ignoring case. Returns false when there's no match.

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Syntax

stripos(string $haystack, string $needle, int $offset = 0): int|false

Parameter	Description
`haystack`	The string to search in.
`needle`	The string to find, in any case.
`offset` optional	Where to start searching. Default: `0`

The position, or false.

Case-insensitive searchTry it yourself

<?php
echo stripos("Learn PHP today", "php"), "\n";
var_dump(stripos("Learn PHP today", "python"));

Output

6
bool(false)

Detect a wordTry it yourself

<?php
$agent = "Mozilla/5.0 (iPhone; CPU iPhone OS 17_0)";
echo stripos($agent, "iphone") !== false ? "mobile" : "desktop", "\n";

Output

mobile

Version	Change
PHP 5.0	Added

strpos() · Find the position of the first occurrence of a substring. Returns false if it's not found, so compare with === false.
str_contains() · Check whether a string contains a substring and return true or false. Case-sensitive; added in PHP 8.0.
PHP Strings · tutorial