Don't know if already posted this, but if I did this is an improvement.

This function will check if a string contains  a needle. It _will_ work with arrays and multidimensional arrays (I've tried with a > 16 dimensional array and had no problem).

<?php
function str_contains($haystack, $needles)
{
    //If needles is an array
    if(is_array($needles))
    {
        //go trough all the elements
        foreach($needles as $needle)
        {
            //if the needle is also an array (ie needles is a multidimensional array)
            if(is_array($needle))
            {
                //call this function again
                if(str_contains($haystack, $needle))
                {
                    //Will break out of loop and function.
                    return true;
                }
                
                return false;
            }

            //when the needle is NOT an array:
                //Check if haystack contains the needle, will ignore case and check for whole words only
            elseif(preg_match("/\b$needle\b/i", $haystack) !== 0)
            {
                return true;
            }
        }
    }
    //if $needles is not an array...
    else
    {
        if(preg_match("/\b$needles\b/i", $haystack) !== 0)
        {
            return true;
        }
    }

    return false;
}
?>