BigInt

In earlier JavaScript version, there is a limitation of using the Number type. i.e, You cannot safely represent integer values(Number primitive) larger than pow(2, 53). In ES2020,

BigInt is introduced as the 7th primitive type to represent whole numbers(integers with arbitrary precision) larger than pow(2, 53) - 1(or 9007199254740991 or Number.MAX_SAFE_INTEGER). This is been created by appending n to the end of an integer literal or by calling the function BigInt().

// 1. Current number system
const max = Number.MAX_SAFE_INTEGER;
console.log(max + 1) // 9007199254740992
console.log(max + 2) // 9007199254740992

// 2. BigInt representation
const bigInt = 9007199254740991n;
const bigIntConstructorRep = BigInt(9007199254740991); // 9007199254740991n
const bigIntStringRep = BigInt("9007199254740991"); // 9007199254740991n

// 3. Typeof usage

console.log(typeof 1)// number
console.log(typeof 1n)// bigint
console.log(typeof BigInt('1'))// bigint

// 4. Operators

const previousMaxNum = BigInt(Number.MAX_SAFE_INTEGER);
console.log(previousMaxNum + 2n); //9007199254740993n (this was not possible before)
console.log(previousMaxNum -2n); //9007199254740990n
console.log(previousMaxNum * 2n); //18014398509481982n
console.log(previousMaxNum % 2n); //1n
console.log(previousMaxNum / 2n); // 4503599627370495n

// 5. comparison
console.log(1n === 1); // false
console.log(1n === BigInt(1)); // true
console.log(1n == 1); // true