Performance of Array vs. Object (v85)

Revision 85 of this benchmark created by Digitale Welten on

Preparation HTML

<script>

// test arrays
var arr = [];
var obj = {};
var obj2 = new Object();
var obj3 = new (function(){
    var $obj3 = function(){
        this.obj = (function(){
            var obj3 = {};
            for(var i = 0; i < 10000; ++i) {
                obj3[i] = { payload: i };
            }
            return obj3;
        }());
    };
    $obj3.prototype.getSum = function() {
        var obj = this, sum = 0;
        for(var key in obj) {
            if(obj.hasOwnProperty(key)) sum += obj[key].payload;   
            return sum;
        }    
    };
    return $obj3;
}());
var sparse = [];
var breaker = {};



//
obj2.constructor.prototype.getKeys = function(){ return Object.keys(this); };
obj2.constructor.prototype.getSum = function(){
    var obj = this, sum = 0, len = obj.getKeys().length;
    for(var i = 0; i < len; ++i) sum += obj[i].payload;   
    return sum;
};
// forEach for assoziative arrays
obj2.constructor.prototype.each = function(obj, iterator, context) {
    //var key; //var obj = this;
    for(var key in obj) {
        if(obj.hasOwnProperty(key)) {
            if(iterator.call(context, obj[key], key, obj) === breaker) return;
        }
    }    
 };
// object array to simple array
obj2.constructor.prototype.getValuesPush = function() {
    var obj = this, values = [];
    for(var key in obj) if(obj.hasOwnProperty(key)) values.push(obj[key]);
    return values;
};

// object array to simple array
obj2.constructor.prototype.getValuesIterate = function() {
    var obj = this, values = [], len = 0;
    for(var key in obj) if(obj.hasOwnProperty(key)) values[len++] = obj[key];
    return values;
};

// object array to simple array
obj2.constructor.prototype.getValuesIndexed = function() {
    var obj = this, len = obj.getKeys().length, values = [];
    for(var i = 0; i < len; ++i) values[i] = obj[i];
    return values;
};


// forEach for assoziative arrays
var each = function(obj, iterator, context) {
    for(var key in obj) {
        if(obj.hasOwnProperty(key)) {
            if(iterator.call(context, obj[key], key, obj) === breaker) return;
        }
    }    
 };


// create arrays
for(var i = 0; i < 10000; ++i) {
  arr.push({ payload: i });
  obj[i] = { payload: i };
  obj2[i] = { payload: i };
  obj3[i] = { payload: i };
}

// create sparsed array
sparse [0] = "a";
sparse [10] = "b";
sparse [9999] = "c";

// cached keys
var keys = Object.keys(obj);



//console.log(obj.getValuesIndexed());
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
Internal Routine via Function Prototype
var sum = obj3.getSum();

if(sum!=49995000) console.log('error: '+sum);
ready
Simple Array [ ] of Objects
var sum = 0, x = 0, len = arr.length;

for (; x < len; ++x) {

  sum += arr[x].payload;
}

if(sum!=49995000) console.log('error: '+sum);
ready
Object Array { } of Objects
var sum = 0;

for (var x in obj) {

  if(obj.hasOwnProperty(x)) sum += obj[x].payload;
}

if(sum!=49995000) console.log('error: '+sum);
ready
Object Iterate (known length)
var sum = 0, x = 0;

for (; x < 10000; ++x) {

  sum += obj[x].payload;
}

if(sum!=49995000) console.log('error: '+sum);
ready
Object > keys() Iterate
var sum = 0, x = 0, len = keys.length;

for (; x < len; ++x) {

  sum += obj[keys[x]].payload;
}

if(sum!=49995000) console.log('error: '+sum);
ready
Array.foreach()
var sum = 0;

arr.forEach(function(val) {

    sum += val.payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Object > keys().foreach()
var sum = 0;

keys.forEach(function(val) {

    sum += obj[val].payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Using Array.reduce()
var sum = arr.reduce(function(a, b) {
    return a.payload + b.payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Object.foreach() Polyfill
var sum = 0;

each(obj, function(val) {

    sum += val.payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Object > Array.foreach() Prototype Push
var sum = 0;

obj2.getValuesPush().forEach(function(val) {

    sum += val.payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Object > Array.foreach() Prototype Iterate
var sum = 0;

obj2.getValuesIterate().forEach(function(val) {

    sum += val.payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Object > Array.foreach() Prototype Indexed
var sum = 0;

obj2.getValuesIndexed().forEach(function(val) {

    sum += val.payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Object > Keys.foreach() non-cached
var sum = 0;
var key = obj2.getKeys();

key.forEach(function(val) {

    sum += obj[val].payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Object.foreach() Prototype Polyfill
var sum = 0;

obj2.each(function(val) {

    sum += val.payload;
});

if(sum!=49995000) console.log('error: '+sum);
ready
Internal Routine via Object Prototype
var sum = obj2.getSum(obj);

if(sum!=49995000) console.log('error: '+sum);
ready

Revisions

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