# The JavaScript Arithmetic operators

> Learn the JavaScript arithmetic operators, from addition, subtraction, multiplication, and division to remainder, exponentiation, increment, and decrement.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2018-07-17 | Updated: 2019-04-27 | Topics: [JavaScript](https://flaviocopes.com/tags/js/) | Canonical: https://flaviocopes.com/javascript-math-operators/

Performing math operations and calculus is a very common thing to do with any programming language.

[JavaScript](https://flaviocopes.com/javascript/) offers several operators to help us work with numbers.

- [Addition (+)](#addition-)
- [Subtraction (-)](#subtraction--)
- [Division (/)](#division-)
- [Remainder (%)](#remainder-)
- [Multiplication (\*)](#multiplication-)
- [Exponentiation (\*\*)](#exponentiation-)
- [Increment (++)](#increment-)
- [Decrement (`--`)](#decrement---)
- [Unary negation (-)](#unary-negation--)
- [Unary plus (+)](#unary-plus-)

## Addition (+)

```js
const three = 1 + 2
const four = three + 1
```

The `+` operator also serves as string concatenation if you use strings, so pay attention:

```js
const three = 1 + 2
three + 1 // 4
'three' + 1 // three1
```

## Subtraction (-)

```js
const two = 4 - 2
```

## Division (/)

Returns the quotient of the first operator and the second:

```js
const result = 20 / 5 //result === 4
const result = 20 / 7 //result === 2.857142857142857
```

If you divide by zero, JavaScript does not raise any error but returns the `Infinity` value (or `-Infinity` if the value is negative).

```js
1 / 0 - //Infinity
  1 / 0 //-Infinity
```

## Remainder (%)

The remainder is a very useful calculation in many use cases:

```js
const result = 20 % 5 //result === 0
const result = 20 % 7 //result === 6
```

A remainder by zero is always `NaN`, a special value that means "Not a Number":

```js
;(1 % 0) - //NaN
  (1 % 0) //NaN
```

## Multiplication (\*)

Multiply two numbers

```js
1 * 2 - //2
  1 * 2 //-2
```

## Exponentiation (\*\*)

Raise the first operand to the power second operand

```js
1 ** 2 //1
2 ** 1 //2
2 ** 2 //4
2 ** 8 //256
8 ** 2 //64
```

The exponentiation operator `**` is the equivalent of using `Math.pow()`, but brought into the language instead of being a library function.

```js
Math.pow(4, 2) == 4 ** 2
```

This feature is a nice addition for math intensive JS applications.

The `**` operator is standardized across many languages including [Python](https://flaviocopes.com/python-introduction/), Ruby, MATLAB, Lua, Perl and many others.

## Increment (++)

Increment a number. This is a unary operator, and if put before the number, it returns the value incremented.

If put after the number, it returns the original value, then increments it.

```js
let x = 0
x++ //0
x //1
++x //2
```

## Decrement (`--`)

Works like the increment operator, except it decrements the value.

```js
let x = 0
x-- //0
x //-1
--x //-2
```

## Unary negation (-)

Return the negation of the operand

```js
let x = 2 - x //-2
x //2
```

## Unary plus (+)

If the operand is not a number, it tries to convert it. Otherwise if the operand is already a number, it does nothing.

```js
let x = 2 + x //2

x = '2' + x //2

x = '2a' + x //NaN
```