javascript private members in prototype

Question

I would like to start that I'm not feeling comfortable with JS.

I've experienced a problem with implementing private methods in prototype. Let's say we have a Person class. I want to expose greet method but keep getName private.

function Person(name) {
    this.name = name;
}

Person.prototype = (function() {

    function getName() {
        return this.name;
    }

    function greet() {
        console.log("hello " + getName());
    }

    return {
        greet: greet
    }
})();

p = new Person('Szymon');
p.greet();

above code won't work as getName doesn't have context ("this" points to window where name doesn't exist).

My solution to this problem was:

function greet() {
    console.log("hello " + getName.call(this));
}

however it's get a little bit messy with bigger class.

Is this a clean solution? I would be grateful for any feedback.

Answer 1

The way you've written it getName is not a method, but a static function. If you don't want to make it a public method (I don't see a good reason why a getter would be private), and don't want to use .call() , then you will need to pass the instance explicitly:

Person.prototype = (function() {

    function getName(self) {
        return self.name;
    }

    function greet() {
        console.log("hello " + getName(this));
    }

    return {
        constructor: Person,
        greet: greet
    }
})();

I'd consider all three solutions equally clean.