2. ES5 and ES6 #

Created Tuesday 14 July 2020

About the JS ecosystem #

"There is nothing static about being a web-developer, everything is improving".

• HTML, CSS are JS evolving very rapidly.
• Even browsers are being updated.
• New libraries are made, existing ones are being improved.
• Now formally called ECMAScript, it interchangeably used with JavaScript.
• ES5 and ES6 introduced new features which make coding very easy and fun.

ECMAScript standards and compatibility #

• Not all browsers support ES5 and ES6 right now, is it practical to learn and use the standard right now?
• Yes, some new features of ESx are not currently supported by all browsers. But we can still use them, we’ll use a compiler to obtain the most supported version of ECMAScript from the latest ESx code. A popular compiler is Babel, it works with the latest ESx. Don’t worry about the version.
• There are two important operations when handling two versions:
  1. Polyfilling - Representing new functionality in old code. No syntax changes should be present between new and old. Only functionality changes.
  2. Transpiling - There are new syntax changes, and the current code needs to be represented in old syntax. Functionality does not matter here.
• Babel does both transpiling and polyfilling.

• The new standards have made the code clean and concise.

Features of ES5 and ES6 #

There are 3 kinds of features introduced by ES5 and ES6:

1. Necessities - critical problems with JS
2. Shorthands and object features - make code concise and dynamic.
3. Exclusive features - new features exclusive to JS