Javascript dependency injection example

js-di-example.js

var Calculator = (function () {
	"use strict";

	function sum(firstNumber, secondNumber) {
		return firstNumber + secondNumber;
	}

	return {
		sum : sum
	};
}());

var DependencyInjectionExample = (function (calculator) {
	"use strict";

	function showExample() {
		return calculator.sum(1, 3);
	}

	return {
		showExample : showExample
	};
}(Calculator));