What Are Var, Let, and Const Keywords in JavaScript?
Learn how to define variables, as well as the differences between the var, let, and const keywords used to declare variables.
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Introduction
To define any variable in JavaScript, there are three keywords: var, let, and const. These keywords can be a bit confusing—let’s get to know them by going over their differences. We’ll start with their scope.
Scope
The scope of a variable defines the accessibility of that variable in the program. In other words, it specifies the area in the program/code where a particular variable can be accessed.
var |
let |
const |
|---|---|---|
Variables declared with var are in the function scope. |
Variables declared as let are in the block scope. |
Variables declared as const are also in the block scope. |
Look at the below code snippets to see this:
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