Nodejs Array Unique unique()

Method Source Code

Array.prototype.unique = function() {
   var arr = [this[0]];

   for (var i = 1; i < this.length; i++) {
      if ( arr.indexOf (this[i]) === -1) {
         arr.push(this[i]);//from   w w w  .j  a  v  a  2s .co m
      }
   }
   return arr;
}


var arr = [1, 2, 1, 3, 5, 3, 5, '5'];
console.log(arr.unique());

console.time();
var unique2 = function(arr) {
   var 
      ary = [],
      i = 0,
      key;

   for (; key = arr[i++]; ) {
      if ( ary.indexOf(key) === -1 ) {
         ary.push(key);
      }
   }

   return ary;
}

console.log(unique2(arr));
console.timeEnd();

Related

1. unique()

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

2. 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());
   

3. 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]);}
   ...
   

4. 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;
   ...
   

5. unique()

   Array.prototype.unique = function() {
     var solution = [];
     for(var i=0; i<this.length; i++) {
       if(solution.indexOf(this[i]) === -1) solution.push(this[i]);
     return solution;
   };
   

6. 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;
   ...
   

7. unique()

   Array.prototype.unique = function() {
     var arr = [];
     for(var i = 0; i < this.length; i++) {
       if(arr.indexOf(this[i]) === -1) {
         arr.push(this[i]);
     return arr;
   };
   ...
   

8. unique()

   Array.prototype.unique=function () {
       var n=[];
       for(var i=0;i<this.length;i++){
           if(n.indexOf(this[i])==-1){
               n.push(this[i]);
       return n;
   

9. unique()

   Array.prototype.unique = function () { 
     return this.filter((a, i) => this.indexOf(a) === i)