JavaScript’s Giant Leap: Mastering BigInt for Accurate Calculations

Unlocking the Power of BigInt in JavaScript

Before the release of ES2020, JavaScript developers faced a significant limitation when working with large numbers. The native Number type couldn’t accurately represent or perform mathematical operations on numbers greater than 9,007,199,254,740,991 or less than -9,007,199,254,740,991. This led to the reliance on libraries like JSBI and bignumber.js. However, with the introduction of BigInt, this limitation was overcome, and JavaScript now has a total of eight data types.

What is BigInt?

BigInt is a numerical data type that can represent both small and large numbers that cannot be represented by the older numerical data type, Number. Every BigInt value must contain a lowercase n after the number, e.g., 897n. This means that 21 is not strictly equal to 21n, as the former is a Number while the latter is a BigInt.

Use Cases for BigInt

BigInt values find their use in applications that handle large numbers, such as:

• Financial calculations: BigInt is essential in financial calculations due to the possibility of handling very large amounts of transactions and currency conversions.
• Cryptography and security computing: BigInts are used in cryptography to generate really large random numbers that are very difficult to predict or crack.
• Game developments: In game developments, large numbers are usually used to hold timestamps, points, and to track progress. The use of BigInt ensures the accurate representation of such values.
• Distributed systems: Distributed systems require unique identities to perform accurately. Since BigInt values are unlimited, they can be used to generate identifiers and keys.

BigInt vs. Number

A Number in JavaScript can be used to represent an integer and even a float, such as 69 and 4.125677, respectively. It includes values that range between 9,007,199,254,740,991 or 253 – 1 and -9,007,199,254,740,991 or -(253 – 1). However, BigInt can be used to represent and perform operations on any size of integer except floats or decimals, including numbers greater than 9,007,199,254,740,991 or less than -9,007,199,254,740,991.

Limitations of the Number Type

The JavaScript Number type is written as a double-precision 64-bit binary format IEEE 754 value, which means that 52 bits are used for significant values while one bit and 11 bits are used for the sign and exponents. This leads to limitations such as:

• Round-off errors and limited precision of numbers
• Inability to perform precise operations outside the minimum and maximum safe integers
• Failure to perform operations outside a MAXVALUE and MINVALUE range

Advantages of Using BigInt

The advantages of using BigInt in JavaScript include:

• Ensuring that we do not encounter round-off errors
• Performing calculations with arbitrary precision
• Safely and precisely performing calculations on integers that are bigger than Number.MAX_VALUE
• Allowing us to set a boundary on the number of bits we want to permit for a calculation
• Improving speed in JavaScript applications

How to Use BigInt in JavaScript

BigInt can be used to perform calculations similar to numbers. To define a BigInt value, we can use the BigInt literal, which is n, or use the BigInt constructor on a string containing integers or on numbers. However, we should be wary about coercing numbers to BigInt using the constructor because numbers might lose precision even before the conversion occurs.

Working with BigInt Methods

There are five different methods you can use with a call on the BigInt class:

• BigInt.prototype.toString()
• BigInt.prototype.valueOf()
• BigInt.prototype.toLocaleString()
• BigInt.asIntN()
• BigInt.asUintN()

Each of these methods has its own use cases and can be used to perform various operations on BigInt values.

BigInt Common Rules and Precautions

To use BigInt without seeing errors, there are rules we need to follow, such as:

• Do not use the new keyword when creating BigInt
• Do not use decimals with BigInt
• Errors with BigInt coercion
• Do not use JSON.stringify directly with BigInt
• Do not use the positive unary operation with BigInt
• Limited built-in methods
• Division operations with BigInt returns a truncated result

By following these rules and understanding the advantages and limitations of BigInt, we can unlock its full potential and perform calculations with large numbers accurately and efficiently.