js笔记

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

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

 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);
    }