Variables in Js

 

What are Variables?

In JavaScript, variables are used to store data. They are an essential part of any programming language, as they allow you to store, retrieve, and manipulate data in your programs.


There are a few different ways to declare variables in JavaScript, each with its own syntax and rules. In this blog post, we'll take a look at the different types of variables available in JavaScript and how to use them.

Declaring Variables

To declare a variable in JavaScript, you use the "var" keyword followed by the name of the variable. 


For example: 

var x;

This declares a variable called "x" but does not assign any value to it. You can also assign a value to a variable when you declare it, like this:

var x = 10;

In JavaScript, you can also use the "let" and "const" keywords to declare variables. The "let" keyword is used to declare a variable that can be reassigned later, while the "const" keyword is used to declare a variable that cannot be reassigned. For example:

let y = 20;
const z = 30;

In this example, "y" is a variable that can be reassigned, while "z" is a constant that cannot be reassigned.

Data Types

In JavaScript, there are several data types that you can use to store different types of data. Some common data types include:


  • Numbers (e.g. 10, 3.14)
  • Strings (e.g. "hello", 'world')
  • Booleans (e.g. true, false)
  • Arrays (e.g. [1, 2, 3])
  • Objects (e.g. { name: "John", age: 30 })