JS冒泡排序

var arr = [2,1,5,3,6,2,9];
for(var i = 0;i < arr.length; i++){
	for(var j = 0; j<arr.length - 1; j++){
		var tem;
		if(arr[j] < arr[j+1]){
			tem = arr[j+1];
			arr[j+1] = arr[j];
			arr[j] =tem;
		}
	}
}
console.log(arr)

打印結果：[9, 6, 5, 3, 2, 2, 1]