Using “Object.create” instead of “new”

Question

Javascript 1.9.3 / ECMAScript 5 introduces Object.create, which Douglas Crockford amongst others has been advocating for a long time. How do I replace new

Answer 1

You have to make a custom Object.create() function. One that addresses Crockfords concerns and also calls your init function.

This will work:

var userBPrototype = {
    init: function(nameParam) {
        this.name = nameParam;
    },
    sayHello: function() {
        console.log('Hello '+ this.name);
    }
};


function UserB(name) {
    function F() {};
    F.prototype = userBPrototype;
    var f = new F;
    f.init(name);
    return f;
}

var bob = UserB('bob');
bob.sayHello();

Here UserB is like Object.create, but adjusted for our needs.

If you want, you can also call:

var bob = new UserB('bob');