In this article, we will show you the difference between BigInt and number data types in JavaScript. And also when to use the BigInt data type
Table of Contents
- BigInt Vs Number
- BigInt is an integer, number is a decimal
- They are implemented differently
- BigInt can handle large numbers
- BigInt is more precise
- BigInt cannot be mixed with numbers
- Built in Math object does not support BigInt
- Coercing BigInt to number may lose precision
- You can compare bigInt with a number
- BigInt is not strictly equal to number
- Operations on BigInt is slow
- When to use BigInt
BigInt Vs Number
BigInt is an integer, number is a decimal
You cannot store 100.20 in a BigInt, because it is an integer and not decimal.
1 2 3 4 5 6 7 8 9 10 | //bigInt var BigNum1=100n; //ok var BigNum2=100.20n; /error //number var Num1=100; //ok var Num2=100.20; /ok |
They are implemented differently
bigInt is stored as arbitrary-precision integers and the number as double-precision 64-bit number.
BigInt can handle large numbers
The number can handle numbers up to 9007199254740991 ( Number.MAX_SAFE_INTEGER). It is a limitation imposed due to the double precision 64 bit number
The BigInt can handle numbers larger than that. BigInt is limited by the available memory of the host system.
BigInt is more precise
Since they are integers, they do not suffer from Floating-point precision problems. Hence operations involving them are more precise.
BigInt cannot be mixed with numbers
bigint can not be mixed with operations where numbers are involved as shown below. The JavaScript will throw Cannot mix BigInt and other types, use explicit conversions error.
1 2 3 4 5 6 7 8 9 | let numVar=100; let bigVar= 100n; console.log(numVar+bigVar); *** Error ***** Cannot mix BigInt and other types, use explicit conversions |
Built in Math object does not support BigInt
We cannot use a BigInt value with methods in the built-in Math object as it only supports number types.
Coercing BigInt to number may lose precision
You can convert bigInt to a number using the Number function. But if the bigInt number is larger than Number.MAX_SAFE_INTEGER then you will loose precision
1 2 3 4 5 6 | let numVar=100; let bigVar= 100n; console.log(numVar+ Number(bigVar)); //200 |
Convert the number to bigInt, but if the number is a decimal number, then you will loose the precision again as bigInt is integer and not decimal.
You can compare bigInt with a number
Comparing a bigInt with a number works correctly.
1 2 3 4 5 6 | console.log(1n < 2) //true console.log(2n > 1) //true console.log(2n > 2) //false console.log(2n >= 2) //true |
BigInt is not strictly equal to number
BigInt is loosely equal to number, But if you use strict equality checker (===) then they are not equal as they differ in their data type
1 2 3 4 5 6 7 | let numVar=100; let bigVar= 100n; console.log(numVar==bigVar) //true console.log(numVar===bigVar) //false |
Operations on BigInt is slow
The arithmetic operations involving BigInt are slower compared to the Floating Point arithmetic of a primitive number.
The floating-point arithmetic is implemented in hardware, Hence it is faster. The Arbitrary-precision arithmetic is entirely implemented in software hence slower.
When to use BigInt
Always use numbers unless you need to support numbers larger than Number.MAX_SAFE_INTEGER.
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