Nowadays JavaScript has three different keywords to declare a variable — var, let and, const. Each has its own properties and particularities. Let’s start by making a simple comparison table ...

JavaScript variables hold a wide variety of information and can be used with virtually any data type. Here's how to use variables to store numbers, text strings, objects, and more.

Creating Variables and Using the JavaScript Alert() Function. ... First, let's declare a variable inside of the script tag: myVariable = 5; Here we've just declared a number.