php 实现一个排序算法找出数组中最大/最小的数

<?php
/**
 * Created by phpStorm.
 * User: BinWei
 * Date: 2019/6/1
 * Time: 19:29
 */


/**
 * @description 获取数组中最大/最小值
 * @param $list
 * @param string $type
 * @return mixed|null
 * @author BinWei
 */
function getMaxOrMin($list, $type = 'max')
{
    $target = null;
    switch ($type) {
        case 'max':
            $target = $list[0];
            unset($list[0]);
            foreach ($list as $key => $value) {
                if ($value > $target) {
                    $target = $value;
                }
            }
            break;
        case 'min':
            $target = $list[0];
            unset($list[0]);
            foreach ($list as $key => $value) {
                if ($value < $target) {
                    $target = $value;
                }
            }
            break;
    }
    return $target;
}


$list = [0, 1, 2, 3, 4, 5, 10, -1];
var_dump(getMaxOrMin($list, 'min'));