Nodejs Array Unique unique()

Method Source Code

Array.prototype.unique = function() {
   var res = [this[0]],
      obj = {};/*from ww  w  . ja  v  a2s  .  com*/

   for (var i = 1; i < this.length; i++) {
      if (!obj[this[i]]) {
         res.push(this[i]);
         obj[this[i]] = 1;
      }
   }
   return res;
}

var arr = ['h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', '!'];
console.log(arr.unique())

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])) {
            continue;
         a.push(this[i]);
         u[this[i]] = 1;
      return a;
   

2. unique()

   Array.prototype.unique = function(){
     var new_array = [];
     var index = 0;
     var value = null;
     for( count=0; count < this.length; count++){
       value = this[count];
       if( new_array.indexOf(value)==-1 ){
         new_array[index++] = value;
     return new_array;
   };
   

3. unique()

   Array.prototype.unique = function () {
       var arrVal = this;
       var uniqueArr = [];
       for (var i = arrVal.length; i--; ) {
           var val = arrVal[i];
           if ($.inArray(val, uniqueArr) === -1) {
               uniqueArr.unshift(val);
       return uniqueArr;
   

4. unique()

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

5. unique()

   Array.prototype.unique = function() {
     return this.reduce(function(accum, current) {
       if (accum.indexOf(current) < 0) {
         accum.push(current);
       return accum;
     }, []);
   

6. unique()

   Array.prototype.unique = function()
       var tmp = {}, out = [];
       for(var i = 0, n = this.length; i < n; ++i)
           if(!tmp[this[i]]) { tmp[this[i]] = true; out.push(this[i]); }
       return out;
   var a = [1,2,2,7,4,1,'a',0,6,9,'a'];
   var b = a.unique();
   console.log(a);
   console.log(b);
   

7. unique()

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

8. unique()

   Array.prototype.unique = function() {
       var a = this.concat();
       for(var i=0; i<a.length; ++i) {
           for(var j=i+1; j<a.length; ++j) {
               if(a[i] === a[j])
                   a.splice(j--, 1);
       return a;
   ...
   

9. unique()

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