javascript冒泡排序

function BubbleSort (arr) {
for (var i = 0; i < arr.length - 0; i++) {
for (var j = 0; j < arr.length - 1 - i; j++) {
if (arr[j] < arr[j+1]) { //如果正序就就改变符号
var temp = arr[j];
arr[j] = arr[j+1];
arr[j+1] = temp;
}
}
}
}
var num = [20,32,43,21,90,8,3,12,36];
BubbleSort(num);
for (var i = 0; i < num.length; i++) {
document.write(num[i] + '<br/>');
};