- var_dump: documentation ( source)
- max: documentation ( source)
<?php
var_dump(max(["8000", "12345"]));
var_dump(max(["8000", "12345", "6811-1"]));
var_dump(max(["8000", "12345", "6811-1", "7031"]));
var_dump(max(["8000", "12345", "6811-1", "7031", "6841"]));