unique in array (v4)

Revision 4 of this benchmark created on

Description

Low number of duplicates

Preparation HTML

<script src="http://documentcloud.github.com/underscore/underscore-min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>

Setup

var arr = [];
    for (var i = 0; i < 10000; i++) {
      arr.push(Math.floor(Math.random()*20000));
    }
    var arrclone1 = arr.slice();
    var arrclone2 = arr.slice();
    var arrclone3 = arr.slice();
    
    var jqFilter = function(v, k){
        return $.inArray(v ,arr) === k;
    }
    
    Array.prototype.unique = function() {
        var a = [];
        for (var i=0, l=this.length; i<l; i++)
            if (a.indexOf(this[i]) === -1)
                a.push(this[i]);
        return a;
    }
    
    Array.prototype.getUnique = 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;
    }
    
    function onlyUnique(value, index, self) { 
        return self.indexOf(value) === index;
    }
    
    Array.prototype.sortFilter = function() {
        var sorted_arr = this.sort();
        var results = [];
        for (var i = 0; i < this.length - 1; i++) {
            if (sorted_arr[i + 1] == sorted_arr[i]) {
                results.push(sorted_arr[i]);
            }
        }
        return results;
    }
    
    Array.prototype.sortUnique = function() {
        this.sort();
        var last_i;
        for (var i=0;i<this.length;i++)
            if ((last_i = this.lastIndexOf(this[i])) !== i)
                this.splice(i+1, last_i-i);
        return this;
    }
    
    Array.prototype.distinct = function () {
        var dups = {};
        return this.filter(function(el) {
            var isDup = dups[el];
            dups[el] = true;
            return !isDup;
        });
    }

Test runner

Ready to run.

Testing in
TestOps/sec
jQuery grep
$.grep(arr, jqFilter);
ready
Underscore uniq
_.uniq(arr)
ready
My arr.unique
arr.unique();
ready
Rafael's arr.getUnique
arr.getUnique();
ready
TLindig's filter
arrclone1.filter(onlyUnique);
ready
swilliams' sorted testing
arrclone2.sortFilter();
ready
My version of sorted testing
arrclone3.sortUnique();
ready
Sorting my arr.unique
arr.unique().sort();
ready
Distinct
arr.distinct();
ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.