default parameters completed.

Author: EhsanZB

02-Part II - ES2015 features/03-Default Parameter/notes.md

@@ -0,0 +1,38 @@
+## Default Parameter
+
+* Old way (ES5):
+
+```js
+function applyDiscount(cost, discount) {
+	discount = discount || .10;
+	return cost - (cost * discount);
+}
+
+console.log(applyDiscount(100)); // 90 (using default 10% discount)
+```
+
+* New way (ES6)
+
+```js
+function applyDiscount(cost, discount = .10) {
+
+	return cost - (cost * discount);
+}
+
+console.log(applyDiscount(100)); // 90 (using default 10% discount)
+```
+
+> note that such default values are not limited to primitive values, it also accepts other values even from another function!
+
+```js
+function defaultDiscount() {
+	return .10;
+}
+
+function applyDiscount(cost, discount = defaultDiscount()) {
+
+	return cost - (cost * discount);
+}
+
+console.log(applyDiscount(100)); // 90 (using default 10% discount)
+```

README.md

@@ -10,7 +10,8 @@ Other useful references:
 * [JavaScript Cookbook](http://shop.oreilly.com/product/0636920033455.do)
 * [JavaScript Pocket Reference](http://shop.oreilly.com/product/0636920011460.do)
 * [Mastering Javascript](https://www.packtpub.com/web-development/mastering-javascript)
-* [envato tuts+](https://tutsplus.com/tutorials/search?utf8=%E2%9C%93&search%5Bterms%5D=JavaScript&button=)
+* [Envato Tuts+](https://tutsplus.com/tutorials/search?utf8=%E2%9C%93&search%5Bterms%5D=JavaScript&button=)
+* [Laracast](https://laracasts.com/)
 
 ### Topics:
 
@@ -38,8 +39,8 @@ Other useful references:
 #### Part II 'ES6/ES2015 Features'
 
 01. Template String
-02. Arrows (arrow functions) 
-03. Default Parameters (_in progress_)
+02. Arrows (arrow functions)
+03. Default Parameters
 04. Rest and Spread (_in progress_)
 05. Template Strings (_in progress_)
 06. Object additions (_in progress_)