PHP str_contains

Summary: in this tutorial, you’ll learn how to use the PHP str_contains() function to check if a string contains a substring.

Introduction to the PHP str_contains() function

The PHP str_contains() function checks if a string contains a substring. Here’s the syntax of the str_contains() function:

str_contains ( string $haystack , string $needle ) : bool
Code language: PHP (php)

The str_contains() function has the following parameters:

  • $haystack is the string to be checked.
  • $needle is the substring to search for in the input string $haystack.

The str_contains() function returns true if the $needle is in the $haystack, false otherwise.

When searching for the $needle in the $haystack, the str_contains() function uses a case-sensitive search.

Note that str_contains() function has been available since PHP 8.0.0. If you use an earlier version of PHP, you can polyfill the str_contains() function like this:

<?php if (!function_exists('str_contains')) { function str_contains( $haystack, $needle) { return $needle !== '' && mb_strpos($haystack, $needle) !== false; }
Code language: PHP (php)

PHP str_contains() function examples

The following example uses the str_contains() function to check if the string 'PHP' is in the string 'PHP string functions':

<?php $haystack = 'PHP is cool.'; $needle = 'PHP'; $result = str_contains($haystack, $needle) ? 'is' : 'is not'; echo "The string {$needle} {$result} in the sentence.";
Code language: PHP (php)

Output:

The string PHP is in the sentence
Code language: PHP (php)

As mentioned earlier, the str_contains() function uses the case-sensitive search for checking if a substring is in a string. For example:

<?php $haystack = 'PHP is cool.'; $needle = 'Cool'; $result = str_contains($haystack, $needle) ? 'is' : 'is not'; echo "The string {$needle} {$result} in the sentence.";
Code language: PHP (php)

Output:

The string Cool is not in the sentence.
Code language: PHP (php)

Summary

  • Use the PHP str_contains() function to carry a case-sensitive search to check if a string is in another string.
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