Nodejs Array Unique unique()

Method Source Code

// JavaScript Document
Array.prototype.unique = function() {
    return this.reduce(function(accum, current) {
        if (accum.indexOf(current) < 0) {
            accum.push(current);// w  ww . java  2s. c o  m
        }
        return accum;
    }, []);
}

function sleep(milliseconds) {
  var start = new Date().getTime();
  for (var i = 0; i < 1e7; i++) {
    if ((new Date().getTime() - start) > milliseconds){
      break;
    }
  }
}

Related

1. unique()

   Array.prototype.unique = function(){
     var u = {},
       a = [];
     for(var i = 0, l = this.length; i < l; ++i){
       if(u.hasOwnProperty(this[i].toString())) {
         continue;
       a.push(this[i]);
       u[this[i].toString()] = 1;
   ...
   

2. unique()

   Array.prototype.unique = function() {
       var r = new Array();
       o: for (var i = 0, n = this.length; i < n; i++) {
           for (var x = 0, y = r.length; x < y; x++) {
               if (r[x] == this[i]) {
                   return false;
           r[r.length] = this[i];
   ...
   

3. unique()

   Array.prototype.unique = function(){
     var array = [];
     var obj = {};
     for(var i = 0; i < this.length; i++){
       if(!obj[this[i]]){
         obj[this[i]] = 1;
         array.push(this[i]);
     console.log(array.length);
     return array;
   };
   var array = new Array();
   array = ['1','2','3','4','12','1','123','2','2','12','4'];
   console.log(array.unique());
   

4. unique()

   Array.prototype.unique = function() {
     var res = [this[0]];
     for (var i = 1; i < this.length; i++) {
       var repeat = false;
       for (var j = 0; j < res.length; j++) {
         if (this[i] == res[j]) {
           repeat = true;
           break;
       if (!repeat) {
         res.push(this[i]);
     return res;
   var arr = ['h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', '!'];
   console.log(arr.unique())
   

5. unique()

   Array.prototype.unique = function () {
       var results  = this.sort();
       for ( var i = 1; i < results.length;i++) {
          if (results[i] === results[i-1]) {
              results.splice(i--,1);
       return results;
   

6. unique()

   Array.prototype.unique = function(){
     var n=[];
     this.forEach(function(v){if(!n.inArray(v)){n.push(v);}});
     return n;
   };
   

7. unique()

   var nums =[{name: 1, val: 1},
   {name: 2, val: 1},
   {name: 3, val: 2},
   {name: 4, val: 2}];
   Array.prototype.unique = function() {
       return this.reduce(function(accum, current) {
           if (accum.indexOf(current) < 0) {
               accum.push(current);
           return accum;
       }, []);
   var newArr = [];
   for (var i = 0; i < nums.length; i++) {
     newArr.push(nums[i].val);
   };
   console.log(newArr.unique());
   

8. unique()

   Array.prototype.unique = function(){
     'use strict';
     var im = {}, uniq = [];
     for (var i=0;i<this.length;i++){
       var type = (this[i]).constructor.name, 
           val = type + (!/num|str|regex|bool/i.test(type) 
                  ? JSON.stringify(this[i]) 
                  : this[i]);
       if (!(val in im)){uniq.push(this[i]);}
   ...
   

9. unique()

   Array.prototype.unique = function () {
       var r = new Array();
       o:for(var i = 0, n = this.length; i < n; i++)
         for(var x = 0, y = r.length; x < y; x++)
           if(r[x]==this[i])
              continue o;
   ...