Table of Contents

## Introduction

Mathematical operations are at the core of programming and computers, and it's because they can do them so much faster than the average human that they have become popular.

One such operation is the division which can be quite complex but made a lot easier with integer division. With typical divisions, there can be a bit of approximation which can be difficult to work with when precision calculations are required (and especially with JavaScript where certain functions are implementation-dependent).

However, with integer division, you can divide two integers and discard the remainder (if any), especially if you only need the number of times (quotient) a number is divisible by another number. In this article, we will discuss how to achieve integer division in JavaScript.

## JavaScript Integer Division Methods

We will make use of two methods and one operator to achieve JavaScript integer division.

### Use floor() method

Within JavaScript, there is an all-powerful `Math`

object that provides a ton of mathematical functionalities from constants to functions. Important to note that, the Math object doesn’t work with `BigInt`

. Within the `Math`

object are static properties and methods that provide mathematics functionalities.

One such static method is the `floor`

method that rounds down its `Number`

type argument. So, for us to achieve integer division, we can do the typical division using the `/`

operator and round down the answer (a floating-point number) using the `floor`

method to give us the `quotient`

- the integer division result.

```
const y = 34;
const x = 12;
const quotient = Math.floor(y / x);
console.log(quotient);
```

Output

```
2
```

If you need the remainder, you can make use of the `modulus`

operator

```
const y = 34;
const x = 12;
const quotient = Math.floor(y / x);
const remainder = y % x;
console.log(`quotient - ${quotient}, remainder - ${remainder}`);
```

Output

```
quotient - 2, remainder - 10
```

It also works with negative numbers.

```
const y = -3231134;
const x = 12;
const quotient = Math.floor(y / x);
const remainder = y % x;
console.log(`quotient - ${quotient}, remainder - ${remainder}`);
```

Output

```
quotient - -269262, remainder - -2
```

### Use trunc() method

While the `floor`

method rounds down, the `trunc`

method simply returns the integer part of a number and removes any fractional digits that are present within a `Number`

value.

So, we can carry out the same operation by changing the `floor`

method to the `trunc`

method to achieve integer division in JavaScript.

```
const y = 34;
const x = 12;
const quotient = Math.floor(y / x);
const remainder = y % x;
console.log(`quotient - ${quotient}, remainder - ${remainder}`);
```

Output

```
quotient - 2, remainder - 10
```

### Use the Bitwise Operator method

There are 7 bitwise operators that can perform binary-based actions on their operands, and treats their operands as a set of 32-bit binary digits. Important to us however is the bitwise `NOT`

operator which inverts the bits of its operand and can help us convert the floating-point number to an integer.

```
const y = 34;
const x = 12;
const quotient = ~~(y / x);
const remainder = y % x;
console.log(`quotient - ${quotient}, remainder - ${remainder}`);
```

Output

```
quotient - 2, remainder - 10
```

So, the code inverts the bits of the division of the numbers twice to give the integer result that we need.

## Summary

To achieve JavaScript integer division, we can make use of two static methods from the Math object - `floor`

and `trunc`

- and one bitwise operator - `NOT`

. With the aid of these features, we can scale integer divisions from small to large numbers. However, all methods don’t work with `BigInt`

numbers.

## References

Math - JavaScript | MDN (mozilla.org)

Math.floor() (mozilla.org)

Math.trunc() - JavaScript | MDN (mozilla.org)