PHP数组练习

一、对数组[21,25,11,32,12,35,55,77,66]进行排序，输出结果为：[77 11 66 12 55 21 35 25 32]

//排序 结果：77 11  66 12 55 21 35 25 32
        $arr = [21,25,11,32,12,35,55,77,66];
        rsort($arr);
        $i = 0;
        $j = 8;
        for ($k=0;$k<=8;$k++){
            if($k%2==0){
                $arrs[] = $arr[$i];
                $i = $i+1;
            }else{
                $arrs[] = $arr[$j];
                $j = $j-1;
            }
        }
        echo "<pre>";
        print_r($arr);
        echo "<pre>";
        print_r($arrs);
        exit();