How to “properly” create a custom object in JavaScript?

Question

I wonder about what the best way is to create an JavaScript object that has properties and methods.

I have seen examples where the person used var self = this<

Answer 1

In addition to the accepted answer from 2009. If you can can target modern browsers, one can make use of the Object.defineProperty.

The Object.defineProperty() method defines a new property directly on an object, or modifies an existing property on an object, and returns the object. Source: Mozilla

var Foo = (function () {
    function Foo() {
        this._bar = false;
    }
    Object.defineProperty(Foo.prototype, "bar", {
        get: function () {
            return this._bar;
        },
        set: function (theBar) {
            this._bar = theBar;
        },
        enumerable: true,
        configurable: true
    });
    Foo.prototype.toTest = function () {
        alert("my value is " + this.bar);
    };
    return Foo;
}());

// test instance
var test = new Foo();
test.bar = true;
test.toTest();

To see a desktop and mobile compatibility list, see Mozilla's Browser Compatibility list. Yes, IE9+ supports it as well as Safari mobile.