https://github.com/jikan-me/jikan-rest/issues/87

test_is_numeric.php

<?php

function getScoredBy($scoredBy):
{
        $scoredByNum = str_replace(
            [',', ' users', ' user'],
            '',
            $scoredBy
        );

        if (!is_numeric($scoredByNum)) {
         return null ;
        }

        return (int) $scoredByNum;
}

var_dump(getScoredBy("- user"));
var_dump(getScoredBy("- users"));
var_dump(getScoredBy("N/A users"));
var_dump(getScoredBy("0 users"));
var_dump(getScoredBy("1,200 users"));
var_dump(getScoredBy("500 users"));
var_dump(getScoredBy(" users"));

/*
OUTPUT:
NULL
NULL
NULL
int(0)
int(1200)
int(500)
NULL
*/