php regex check if string contains code example

Example 1: php find if string contains

if (strpos($string, 'substring') !== false) {
	// do stuff 
}

Example 2: contains php

if (strpos($a, 'are') !== false) {
    echo 'true';
}

Example 3: php check if string contains

// returns true if $needle is a substring of $haystack
function contains($haystack, $needle){
    return strpos($haystack, $needle) !== false;
}