冒泡排序

function maopao(){    $testData = array(1,3,7,4,3,8,3,5,7,21);    for($i =0;$i<count($testData);$i++) {        for ($x = $i + 1; $x < count($testData); $x++) {            if ($testData[$x] < $testData[$i]) {                $temp = $testData[$i];                $testData[$i] = $testData[$x];                $testData[$x] = $temp;            }        }    }            foreach ($testData as $value)                echo $value;}