1.冒泡排序
$number = array(9, 8, 7, 6, 5, 4, 3, 2, 1);
for ($i = 0; $i < count($number); $i++) {
for ($j = 0; $j < count($number) - $i - 1; $j++) {
if ($number[$j] > $number[$j + 1]) { //< 降序 > 升续
$temp = $number[$j];
$number[$j] = $number[$j + 1];
$number[$j + 1] = $temp;
}
}
}