test.html

<script>
// javascript 에서 JAVA class 같은게 필요한가???
function Class(arg1=1, arg2=2, arg3=3) { // public class, private vars with default values.
	const name = "name: private final/const var."; // private final var.
	let some = 10; // private var.

	this.var1 = "local public var1"; // public var.

	this.getName = function() { // public method.
		return name;
	};
	this.getSome = function() {
		return some;
	};
	this.increaseSome = function() {
		some++;
	};
	this.getArg1 = function() {
		return arg1;
	};
	this.setArg1 = function(v) {
		arg1 = v;
	};
	this.getArgs = function() {
		return [arg1, arg2, arg3];
	};
	this.toString = function() {
		return "This is Class."
	};
	this.accessSuperClassVar1 = function() {
		return `I can access "${this.__proto__.superClassVar1}"`;
	};

	return "What happens if Class return a value.";
};

function superClass(arg1, arg2, arg3) {

};

// static var/method 같은게 javascript 에 필요한가???
// 그냥 outside 에 있는거랑 다른 이점이 있나?
const classPrototype = {
	superClassVar1: "superClassVar1 is set." // static var? or super class var?
	,superClassMethod: function() { // static method? or super class method?
		return "This is superClassMethod.";
	}
	,accessSubClassVar: function() {
		return this.var1;
	}
};
Class.prototype = classPrototype;

const result = Class("hello", "this", "that");
console.log(result);
const clazz = new Class("hello", "this", "that");
console.log(clazz);
// console.log(clazz.getArgs());
// console.log(clazz.getName());
// clazz.increaseSome();
// console.log(clazz.getSome());
// console.log(clazz.var1);
// clazz.setArg1("arg1 is revised.");
// console.log(clazz.getArg1());
// console.log(clazz.getArgs());
// console.log(clazz.superClassVar1);
// clazz.superClassVar1 = "superClassVar1 is revised in clazz.";
// console.log(clazz.superClassVar1);
console.log(clazz.accessSuperClassVar1());
console.log("Super can access?", clazz.accessSubClassVar());

const clazz1 = new Class("do", "it", "again");
console.log(clazz1.getArgs());
console.log(clazz1.getName());
clazz1.increaseSome();
console.log(clazz1.getSome());
console.log(clazz1.superClassVar1);
clazz.__proto__.superClassVar1 = "superClassVar1 is revised in clazz.__proto__."
console.log(clazz1.superClassVar1);
console.log(classPrototype);

function getArgs() {
	return arguments;
}
const caller = {call:getArgs};
console.log(getArgs("a", "b", "c", "Call from nothing."));
console.log(window.getArgs("a", "b", "c", "Call from window."));
console.log(caller.call("a", "b", "c", "Call from caller."));

function optionalReturn(v) {
	if (v===1) {
		return true;
	}
}
console.log(optionalReturn(1));
console.log(optionalReturn(0));
</script>