max.php

<?php
    $list = array(3,4,2,5,6,7,8,2,5,1,4,4,6);

    function maximum($list) 
    {
    	$len = count($list);
    	$maximum = $list[0];
    	
    	for ($i = 1; $i &lt; $len; $i++) {
    		if ($maximum &lt; $list[$i]) {
    			$maximum = $list[$i];
    		}
    	}
    	
    	return $maximum;
    }

    // 8
    echo maximum($list);