test2

[hibehero]

`

var num = 123456789;
function format(num) {
    var str = num.toString().split('').reverse().join(''); 
    str = str.replace(/\d{3}(?!$)/g,"$&,");
    return str.split('').reverse().join('');
}
//console.log(format(num))
function format1(num) {
    var str = num.toString();
    return str.replace(/\d(?=(\d{3})+$)/g,"$&,")
}
console.log(format(num))



var str = '1232311a'
var reg = /^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{6,}/g;
var rs = reg.test(str);


/*
    洗牌算法，核心按序遍历数组，
    规则：遍历数组时随机选中一个需要交换的位置两两交换直到遍历结束
*/
var arr = [1, 2, 6, 4,8, 6];
function rondomArr(arr) {
    var len = arr.length;
    var clone = arr.slice(0);
    for (var i = 0; i < len; i++) {
        var index = Math.floor(Math.random()*len);
        var temp = clone[index];
        clone[index] = clone[i];
        clone[i] = temp;
        console.log(clone)
    }
    return clone;
}
/*
    每次根据数组的长度随机生成数组的下标，
    通过下标选中要插入结果的项
    每次插入完之后删除原先数组中的项，
    如此循环
*/
function rondomArr1(arr) {
    var clone = arr.slice(0);
    var result = [];
    var index;
    while(clone.length > 0) {
        index = Math.floor(Math.random() * clone.length);
        result.push(clone[index]);
        clone.splice(index, 1)
    }
    return result;
}


/*
     找到最大值和最小值，这个需求可以把它当做给数组进行排序
     冒泡排序法
*/
function findMaxAndMin(arr) {
    var len = arr.length;
    var clone = arr.slice(0);
    var tmp;
    for (var i = 0; i < len; i++) {
        for (var j = 0; j < len-i-1; j++) {
            if (clone[j] > clone[j+1]) {
                tmp = clone[j];
                clone[j] = clone[j+1];
                clone[j+1] = tmp;
            }
        }
    }
    return {
        max: clone[len - 1],
        min: clone[0]
    };
}

`