In this post, I will tell you what is variables in Javascript and how to declare variables in Javascript and pass values like numbers, strings, etc.

Variables in Javascript

let myName = "codeyup";
console.log(myName);

Output: codeyup

In the above example, I have declared a variable (myName) using let whose value is codeyup and it is a string. You will read more about var, let, and const in the next blog posts.

let a = 21;
let b = 39;
console.log(a + b);

Output: 60

In the above example, I have declared two variables (a and b) whose values are 21 and 39. These are Number data types.

Note: Values that we write in ” “ are treated as a string value. Suppose I write “4” then it is a string data type.

let a = "2"; //It is a string data type
let b = 2; //it is a number data type

Ways to declare variables in Javascript

These are some ways to declare variables in Javascript

1. Camel case

let myAddress;

You can also write the first alphabet in capital if you want to write in that way.

2. Underscore

let my_Address;

You can write the second word by using an underscore.

3. Using the $ symbol

let my$Address;

You can write the second word by using an $ symbol.

Note:

When declaring a variable in javascript, do not use the reserved Javascript keywords for declaring a variable.

For example:

let function = 160;

This way of declaring a variable is not allowed in Javascript. But you can declare it by adding $ at the beginning. See the below code.

let $function = 20;
console.log($function);

This way you can declare it. The output of the above is 20.