JavaScript types

javascript provide different data type to hold a different type of value. The set of types in JavaScript consists of two types of data primitive data type and nonprimitive data type.

1. Primitive data type
2. Non-primitive data type

JavaScript has the primitive data types:

• All types except objects define immutable values (that is, values that can't be changed).

FOR Example : There are different types of data that we can use in a JavaScript program.

let data = 5;  //data is a number
let b = "Hello";  //data is a number
let data = true; //data is boolean
let data = null;  //data is a null

• To get the current type of the value that the variable stores, you use the typeof operator:

let data  = 5;  
consol.log(typeof(data)); //data is a number

let data  = "Hello";  
consol.log(typeof(data)); //data is a string

let data  = true; 
consol.log(typeof(data)); //data is boolean

let data  = null;  
consol.log(typeof(data)); //data is a null

Output :

"number" //5 is an integer data.
"string" // "Hello" is an string .
"boolean"//true is an boolean 
"null" // null is an null

• There are 7 basic primitive data types in JavaScript. They are:

Let's see each data type one by one.

Javascript String :

String is used to store text. In JavaScript, strings are enclosed by quotes:

• Single quotes: 'Hello'
• Double quotes: "Hello"
• Backticks: `Hello` FOR Example :

//strings example
const name = 'ram';
const name1 = "hari";
const result = `The names are ${name} and ${name1}`;

• Single quotes and double quotes are practically the same and you can use either of them.
• Backticks are generally used when you need to include variables or expressions into a string. This is done by wrapping variables or expressions with ${variable or expression} as shown above.

Javascript Number :

• Number represents integer and floating numbers (decimals and exponentials). FOR Example :

const number1 = 3;
const number2 = 3.433;
const number3 = 3e5 // 3 * 10^5

• A number type can also be +Infinity, -Infinity, and NaN (not a number). FOR Example :

const number1 = 3/0;
console.log(number1); // Infinity

const number2 = -3/0;
console.log(number2); // -Infinity

// strings can't be divided by numbers
const number3 = "abc"/3; 
console.log(number3);  // NaN

Output :

Infinity
-Infinity
NaN

JavaScript Boolean :

The boolean datatype variable holds only one value, which can be true or false, in lowercase.

Consider the following example:

Declares two variables that hold boolean values. FOR Example :

let dataChecked = true;
let valueCounted = false;

JavaScript Undefined :

The undefined data type represents value that is not assigned.

If a variable is declared but the value is not assigned, then the value of that variable will be undefined.

FOR Example :

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

Output :

undefined

JavaScript null :

null is a special value that represents empty or unknown value.

javascript defines that null is an empty object pointer.

null is not the same as NULL or Null.

FOR Example :

const number = null;
//The number variable is empty.

JavaScript Bigint :

In JavaScript, Number type can only represent numbers less than (253 - 1) and more than -(253 - 1). However, if you need to use a larger number than that, you can use the BigInt data type.

A BigInt number is created by appending n to the end of an integer.

BigInt was introduced in the newer version of JavaScript and is not supported by many browsers including Safari.

JavaScript symbol :

his data type was introduced in a newer version of JavaScript (from ES2015).

A value having the data type Symbol can be referred to as a symbol value. Symbol is an immutable primitive value that is unique.

for example :

// two symbols with the same description

let value1 = Symbol('js');
let value2 = Symbol('js');

Though value1 and value2 both contain 'js', they are different as they are of the Symbol type

JavaScript has the non-primitive data types:

In javascript, non-primitive data types can hold collections of values and more complex entities.

Let’s discuss each one of them in detail.

JavaScript Object

An object is a complex data type that allows us to store collections of data.

avaScript objects are written with curly braces {}. The properties are stored in key value pairs. Property values can be values of any type, including other objects

For Example :

var product = {name: "Watch", price: 50.20, quantiy: 20, description: "It is product description"};

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