By Microsoft Team

 

Summary: in this tutorial, you’ll learn about the TypeScript number data types. 

 

All numbers in TypeScript are either floating-point values or big integers. The floating-point numbers have the type number while the big integers get the type bigint.

 

The number type 

 

The following shows how to declare a variable that holds a floating-point value:

 

let price: number;

 

Or you can initialize the price variable to a number:

 

let price = 9.95;

 

As in JavaScript, TypeScript supports the number literals for decimal, hexadecimal, binary, and octal literals:

 

Decimal numbers 

 

The following shows some decimal numbers:

 

let counter: number = 0;
let x: number = 100, 
    y: number = 200;

 

Binary Numbers 

 

The binary number uses a leading zero followed by a lowercase or uppercase letter “B” e.g., 0b or 0B :

 

let bin = 0b100;
let anotherBin: number = 0B010;

 

Note that the digit after 0b or 0B must be 0 or 1.

 

Octal Numbers

 

An octal number uses a leading zero followed the letter o (since ES2015) 0o. The digits after 0o are numbers in the range 0 through 7:

 

let octal: number = 0o10;

 

Hexadecimal numbers 

 

Hexadecimal numbers use a leading zero followed by a lowercase or uppercase letter X (0x or 0X). The digits after the 0x must be in the range (0123456789ABCDEF). For example:

 

let hexadecimal: number = 0XA;

 

JavaScript has the Number type (with the letter N in uppercase) that refers to the non-primitive boxed object. You should not use this Number type as much as possible in TypeScript. 

 

Big Integers 

 

The big integers represent the whole numbers larger than 253 – 1. A Big integer literal has the n character at the end of an integer literal like this:

 

let big: bigint = 9007199254740991n;

 

Summary 

 

  • All numbers in TypeScript are either floating-point values that get the number type or big integers that get the bigint type.
  • Avoid using the Number type as much as possible.