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 ...

undefined. In JavaScript if a variable has been declared, but has not been assigned a value, is automatically assigned the value undefined . Therefore, if you try to display the value of such variable ...

JavaScript also allows variables to be defined without assigning a value to them, in that case they will have the value undefined. JavaScript's variables provide a way to store and manipulate data, ...

In JavaScript, hoisting is a phenomenon in which variable and function declarations are moved to the top of their respective scope, either global or local. This mechanism may appear confusing at first ...