数组算法

//将a，b的值交换
var a=1，b=2;
var c;
c=a;
a=b;
b=c;

//按照数字大小排序
 var nums = [2, 1, 57, 4, 84, 9, 4];
        var c;
        for (var i = 0; i <= nums.length; i++) {
            for (var j = i; j < nums.length; j++) {
                if (nums[i] < nums[j]) {
                    c = nums[i];
                    nums[i] = nums[j];
                    nums[j] = c;
                }
            }
        }
        console.log(nums)
        
//二维数组
var ps=[
            ["3","2","1"],
            ["w","s","d"],
            ["a","z","f"]
        ]
        for(var i=0;i<ps.length;i++){
            for(var j=0;j<ps[i].length;j++){
                console.log(ps[i][j])
            }
        }