Performance test for object creation

perf.js

/**
 * Performance test for object creation
 *
 * See: http://javascriptweblog.wordpress.com/2010/03/16/five-ways-to-create-objects/
 */


// 4. Simple constructor for new
var TInScope = function () {
    this.test_prop = "4. Simple constructor for new";
    this.to_string = function () {
        return this.test_prop;
    }
};


// 5. Prototype with Constructor for new
var TPrototype = function () {
    this.test_prop = "5. Prototype with Constructor for new";
};

TPrototype.prototype.to_string = function () {
    return this.test_prop;
};

// 3. Constructor using object literal
var TDict = function () {
    var that = {};
    that.test_prop = "3. Constructor using object literal";
    that.to_string = function () {
        return this.test_prop;
    }
    return that;
}

/* Example output:

$ node ./perf1.js
4. Simple constructor for new : 732 ms
5. Prototype with Constructor for new : 343 ms
3. Constructor using object literal : 1154 ms

 */


function do_test(test_obj) {
    var start = new Date();
    var objs = [];

    for (var i=0; i<1000000; i++) {
        objs.push(new test_obj());
    }

    var end = new Date();
    console.log((new test_obj().to_string()),":", end-start,"ms");
}

do_test(TInScope);
do_test(TPrototype);
do_test(TDict);