Class 06
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Javascript
JavaScript (JS) is a lightweight, interpreted, or just-in-time compiled programming language. It is a prototype-based, multi-paradigm, single-threaded, dynamic language, supporting object-oriented, imperative, and declarative (e.g. functional programming) styles. In other words, Javascript is a very versatile programming language, used most commonly to provide functionality to websites but also used in some cases offline such as Node.js. The standards for JavaScript are the ECMAScript Language Specification. We are currently on version six, also known as ES6.
Javascript Varibales
Javascript offers variables which allow you to store information with a quick and easy to reference name. Javascript variables are declared with var, let and const.
The var keyword is used in all JavaScript code from 1995 to 2015. The let and const keywords were added to JavaScript in 2015.
As a general rule: always use const to declare variables unless you think the variable may change. Then use let.
An example for this from w3schools;
const price1 = 5;
const price2 = 6;
let total = price1 + price2;
The two variables price1 and price2 are declared with the const keyword.
These are constant values and cannot be changed.
The variable total is declared with the let keyword.
This is a value that can be changed.