mathjs/docs/reference/functions/round.md

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser and offers an integrated solution to work with numbers, big numbers, complex numbers, units, and matrices.

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# Function round

Round a value towards the nearest integer.
For matrices, the function is evaluated element wise.


## Syntax

```js
math.round(x)
math.round(x, n)
```

### Parameters

Parameter | Type | Description
--------- | ---- | -----------
`x` | number &#124; BigNumber &#124; Fraction &#124; Complex &#124; Array &#124; Matrix | Number to be rounded
`n` | number &#124; BigNumber &#124; Array | Number of decimals Default value: 0.

### Returns

Type | Description
---- | -----------
number &#124; BigNumber &#124; Fraction &#124; Complex &#124; Array &#124; Matrix | Rounded value


## Examples

```js
math.round(3.2);              // returns number 3
math.round(3.8);              // returns number 4
math.round(-4.2);             // returns number -4
math.round(-4.7);             // returns number -5
math.round(math.pi, 3);       // returns number 3.142
math.round(123.45678, 2);     // returns number 123.46

var c = math.complex(3.2, -2.7);
math.round(c);                // returns Complex 3 - 3i

math.round([3.2, 3.8, -4.7]); // returns Array [3, 4, -5]
```


## See also

[ceil](ceil.md),
[fix](fix.md),
[floor](floor.md)