JavaScript BigInt

BigInt is a special numeric type in JavaScript that allows you to represent integers with arbitrary precision. It was introduced in ECMAScript 2020 to handle numbers larger than the Number.MAX_SAFE_INTEGER (2^53 – 1) and smaller than Number.MIN_SAFE_INTEGER (-(2^53 – 1)).

1. Creating BigInt

You can create a BigInt by appending an n to the end of an integer literal or by using the BigInt() function.

// Using the 'n' suffix
let bigIntNum = 1234567890123456789012345678901234567890n;

// Using the BigInt() function
let bigIntNum2 = BigInt('1234567890123456789012345678901234567890');

2. BigInt vs Number

BigInt is designed for precise integer arithmetic, whereas Number is a double-precision floating-point number.

let bigInt = 9007199254740991n; // BigInt
let number = 9007199254740991;  // Number

console.log(bigInt + 1n);  // Output: 9007199254740992n
console.log(number + 1);   // Output: 9007199254740992 (but can't go beyond safely)

Key Differences:

• BigInt can handle very large integers without losing precision.
• Number has a safe integer limit (Number.MAX_SAFE_INTEGER).

3. BigInt Arithmetic

You can perform standard arithmetic operations with BigInt, similar to regular numbers. However, both operands must be BigInts.

let a = 1000000000000000000n;
let b = 2000000000000000000n;

console.log(a + b);  // Output: 3000000000000000000n
console.log(a - b);  // Output: -1000000000000000000n
console.log(a * b);  // Output: 2000000000000000000000000000000000000n
console.log(b / a);  // Output: 2n
console.log(b % a);  // Output: 0n

Note: Division with BigInt returns a whole number.

4. Mixing BigInt and Number

Mixing BigInt and Number in an operation will result in a TypeError. You need to convert the Number to a BigInt or vice versa.

let bigInt = 100n;
let number = 50;

// Convert Number to BigInt
console.log(bigInt + BigInt(number));  // Output: 150n

// Convert BigInt to Number (use cautiously for very large values)
console.log(Number(bigInt) + number);  // Output: 150

5. Comparisons

You can compare BigInt with other BigInt values or numbers using comparison operators.

let bigInt = 100n;
let number = 100;

console.log(bigInt > number);   // Output: false
console.log(bigInt === BigInt(number));  // Output: true

Note: Strict equality (===) will return false if comparing a BigInt and a Number, even if their values are the same.

6. BigInt Methods

• toString(): Converts a BigInt to a string.

  let bigInt = 12345678901234567890n;
  console.log(bigInt.toString());  // Output: "12345678901234567890"
  

  Try It Now

• toLocaleString(): Converts a BigInt to a locale-specific string.

  let bigInt = 12345678901234567890n;
  console.log(bigInt.toLocaleString());  // Output: "12,345,678,901,234,567,890"
  

  Try It Now

7. Use Cases for BigInt

• Cryptography: Handling large numbers for encryption.
• Scientific Calculations: Performing calculations that require high precision.
• Financial Applications: Managing large financial transactions without losing precision.

Summary of JavaScript BigInt

• BigInt is used for working with very large integers.
• Arbitrary Precision: BigInt can represent integers with more precision than Number.
• Arithmetic Operations: Supports addition, subtraction, multiplication, division, and modulo.
• No Mixing: Cannot mix BigInt and Number directly in operations.

BigInt provides a reliable way to handle large integers in JavaScript, ensuring precision and correctness in calculations that go beyond the capabilities of the standard Number type.