Data Types in JavaScript

JavaScript Data Types in JavaScript

In this tutorial, you will learn all about data types in JavaScript with examples

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There are so many data types in JavaScript. But let's look at some of them.

var a = 5; // 5 is a number
let greet = 'hello'; // hello is here text or string'
const message = `hey let's go outskirts tomorrow.` // a simple simple sentence with `backtick`

From the above code snippet, we can see lots of things, var, let, const, number, strings, etc. Today's topic lies all around this.

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JavaScript Data Types

BigInt : Value suffixes with n here are treated as BigInt.

BigInt and Symbol are introduced in a newer version of JavaScript.

Symbol are always unique.

object key and value representation.

Except object all are primitive data types. Only object is treated as a non-primitive type. Primitive Data Type holds only one type of data. ButNon-Primitive Data types hold sets of data in them. For example let array = [ 1, 2, 3, 'hello' , true ]

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Hope we got some idea now about data types. Let's dig inside more in-depth one by one now.

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1. Number

Any integer, float, fraction, or exponential values are treated as numbers.

var num1 = 400; // integer or positive integer
var num2 = -500; //negative integer

var num3 = 20.52; // float or positive float value
var num4 = -20.52; //negative float value

var num5 = 0x000; // hexadecimal
var num6 = 256e-5; // exponential
var num7 = 050; // octal
var num8 = 0c0010001; // binary

2. String

Any character or textual format literals are called String. Strings can be assigned by using three ways:

• single quote - 'hello'
• double quote - "hello"
• one is using backticks``

let a = 'd' // using single quote
let subject = "math" // using double quote
let message = `Visit India. It's a beautiful place in the world.` // using backticks

3. Boolean

In JavaScript, Boolean data types support either true or false. Any condition or statement can be either truthy or falsely. 0 is treated as false and 1 is treated as true.

let user = true; 
console.log(user) // true
let password = false;
console.log(password) // false

4. undefined

Implicitly, any variable with no value assigned to that variable is always undefined. In the backend, all variables are first assigned to an undefined value. if we try to access any variable before assigning the value is undefined

console.log(user) // undefined
let user;

we can also explicitly assign undefined to any variable.

let user = undefined

5. null

null is treated as the empty value in JavaScript. Variable assigned with null means that variable is empty or unknown.

let count = null; // null is assigned to variable count

6. BigInt

If you wish to store the large number in JavaScript we can use BigInt data type. It is appended by n.

For example

let largeNum = 122222222222223333333n; // appended by `n`
let lgNum = 1n;

Remember not all browser support BigInt now.

7. Symbol

Symbol is used to store unique values. values with the same description are treated as unique in JavaScript.

For Example

// This is an example of a Symbol Data type with unique values but with the same description. 
let name1 = Symbol('abhishek') // Unique
let name2 = Symbol('abhishek') // Unique

Here, name1 and name2 both are unique. It can be a used case to provide a unique id to the user but it's not recommended. Just a fun fact !!!😉.

8. Object

Arrays and Objects are non-primitive types and can store sets of values.

For example

let states = [ 'Karanataka' , 'Jaipur', true , 1 , 0 , undefined, null ];

let students = {
fname: 'abhishek',
lname: 'sharma',
course: 'fsjs',
contact: 'abhishek7329sharma@gmail.com'
mobile: 911XXXXXXX
}

// representation of keys and values in a single entity is called an object.

Here, students is an object. Keys are fname , lname , course, etc. Values are abhishek, sharma, fsjs, etc.

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typeof

There is one more important thing we should learn if we have come so far that is typeof. It's important that we should learn how to find the type of any variable.

let name = 'John'
let value = 1
console.log(typeof(name)) // String
console.log(typeof value) // Number
// similarly we can get type of any variable like this

Remember we can use typeof with both parenthesis and without parenthesis.

If you are reading this still CONGRATULLATIONS!!! 🥳 you have come so far and understood a lot in this tutorial about data types. If you find it meaningful then 👍 like this blog motivate me to share more concepts about JavaScript in the future.

Thanks!!! 👋👋👋👋 Bye.