What is BigInt in JavaScript?

BigInt is a built-in object that provides a way to represent a whole number larger than 2⁵³ - 2, which is the largest number JavaScript can represent with Number. BigInt is created by appending n to the end of an integer literal or invoking the BigInt function that creates bigints from string, number etc.

EXAMPLE!

// wasys to create BigInt
const bigint = 12345678901234567890n; 

// string => BigInt
const bigint1 = BigInt("12345678901234567890"); 

// number => BigInt
const bigint2 = BigInt(10);

Maths operators

BigInt is mostly used like regular number, but we can't mix bigints and regular numbers. Example:

const bigint = 10n; 
const bigint1 = 20n; 
const number = 10; 
console.log(bigint + bigint1); // 30n 
console.log(bigint + number); 
// typeerror: cannot mix BigInt and other types

We should explicitly convert them if needed, either using BigInnt() or Number().

// number => bigint
console.log(bigint + BigInt(number)); 

// bigint => number
console.log(Number(bigint) + number);

Comparison: Comparisons such as <, > work with bigints and numbers are just fine. Number and BigInts can be equal(==) but can't be strictly equal(===).

Example:

// Greater or lesser
const bigint = 20n; 
const bigint1 = 10n; 
const number = 10; 
console.log(bigint > bigint1); //true
console.log(bigint ? number); // true

// equals comparison
const bigint = 10n; 
const number = 10; 
console.log(bigint == number); // true
console.log(bigint === number); // false

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