PHP四种排序算法(一冒泡排序)

$arr = [3,2,5,1,7,6];
function maopao($arr)
{
    $len = count($arr);
    if ($len <= 1) {
        return $arr;
    }
    for ($i = 0; $i < $len; $i++) {
        for ($j = 0; $j < $len - $i - 1; $j++) {
            if ($arr[$j] > $arr[$j + 1]) {
                $temp = $arr[$j];
                $arr[$j] = $arr[$j + 1];
                $arr[$j + 1] = $temp;
            }
        }
    }
    return $arr;
}
var_dump(maopao($arr));
array(6) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
  [3]=>
  int(5)
  [4]=>
  int(6)
  [5]=>
  int(7)
}