JS code to randomly select x non-duplicate data from an array

This article mainly introduces the JS code for randomly picking x pieces of non-duplicate data from an array. Friends in need can refer to it

Some operations related to arrays are often encountered in work

1. Randomly select x pieces of unique data from the data (PS: S.each below is the KISSY.each method, you can change it to a for loop)

/*
从数组arr中随机取x条不重复的数据
 */
 function myRand(arr,num){
    var newArr = [];
    rand(num);    //随机 x 个

    function rand(k){
        if(k==0){
            return;
        }
        var index = Math.floor(Math.random() * arr.length);
        var flag = true;
        S.each(newArr,function(v){
            if(v == arr[index]){
                flag = false;
            }
        });
        if(flag){
            newArr.push(arr[index]);
            k--;
        }
        rand(k);
    }
    return newArr;
 }

2. From the object Randomly select x pieces of unique data

/*
随机从对象obj中取x条
 */
function myRand(){
    var S = KISSY;
    var obj={
        '01':{name:'a'},
        '02':{name:'b'},
        '03':{name:'c'},
        '04':{name:'d'},
        '05':{name:'e'},
        '06':{name:'f'},
        '07':{name:'g'},
        '08':{name:'h'},
        '09':{name:'i'},
        '10':{name:'g'}
    };
    var arr = [];
    S.each(obj,function(v,k){
        arr.push(k);
    });
    //随机取3个
    var newArr = myRand(arr,3);
    S.each(newArr,function(b){
        console.log(obj[b]);
    })
};

3. Remove duplicates from the array

/*
去除数组的重复项
 */
function uniqArr(arr){
    function toObject(a) {
        var o = {};
        for (var i=0, j=a.length; i<j; i=i+1) {
            o[a[i]] = true;
        }
        return o;
    };
    function keys(o) {
        var a=[], i;
        for (i in o) {
            if (o.hasOwnProperty(i)) { // 这里, YUI源码中是lang.hasOwnProperty(o, i)
                a.push(i);
            }
        }
        return a;
    };
    return keys(toObject(arr));
}

The above is the entire content of this chapter. For more related tutorials, please visit JavaScript Video tutorial !