JavaScript, Version Controlling and NoSQL

Today we are gonna talk about JavaScript, Version controlling and NoSQL. In JavaScript (js), we are going to know what is js, classes, objects and prototypes, how 'this' key works, strict notation, function closure, callbacks and promises. When it comes to Version controlling, we are gonna talk about what and why? terminology, best practices and GIT. Latter part, we are gonna learn about what is NoSQL, pros and cons and MongoDB.

JavaScript

JavaScript is a scripting or programming language that allows you to implement complex features on web pages. Web pages are not the only place where JavaScript is used. Many desktop and server programs use JavaScript. Node.js is the best known. JavaScript was invented by Brendan Eich in 1995, and became an ECMA standard in 1997. ECMA-262 is the official name of the standard. ECMAScript is the official name of the language. ECMAScript is often abbreviated to ES. ES5 and ES6 are the most widely using versions. ES9 was released in 2018.

There is a problem. Browser is the runtime environment for JavaScript. Most of the browsers know ES5 and some browsers know ES6 upto some extend. So, how browser will understand ES7 or ES8 syn-taxes? There is a JavaScript library called babel, transcompiler that is mainly used to convert ECMAScript 2015+ code into a backwards compatible version of JavaScript that can be run by older JavaScript engines. Babel is a free and open-source.

JavaScript is synchronous, single threaded language, but I/O operations are asynchronous. Therefore, we cannot exactly say JavaScript is synchronous or asynchronous in one word. JavaScript determines variable types, ordering, etc in runtime. JavaScript supports OOP as well as functional programming (Multi paradigm).

JavaScript Classes & Objects