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.

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 ...

The JavaScript executes within the larger context of the surrounding code— that’s why you can reference the variables. Now we start to see some of the power that has made JSX so successful.

First, it’s important to note that JavaScript’s values have fixed types, but variables do not. A JavaScript variable is dynamically typed, so it adopts whatever the type of its value is: ...