js笔记

Posted 2020-08-23 坚持不懈,才能出彩

1.克隆对象

克隆数组：

var country=[‘中国‘,‘美国‘];
var copyCountry=country.slice(0);

克隆对象:

var people={sex:‘man‘,age:4};
var me=JSON.parse(JSON.stringify(people));

2.随机数

从数组中随机取n个不重复的元素

 function getRandomArrayElements(arr, count) {
        var shuffled = arr.slice(0), i = arr.length, min = i - count, temp, index;
        while (i-- > min) {
            index = Math.floor((i + 1) * Math.random());
            temp = shuffled[index];
            shuffled[index] = shuffled[i];
            shuffled[i] = temp;
        }
        return shuffled.slice(min);
    }