# JavaScript Math.round() Function Tutorial

JavaScript provides the Math.round() function in order to round a given number which is generally a float or double into the nearest integer. The Math.round() function is supported by all major browsers completely.

## Math.round() Function Syntax

Math.round() function has a very simple syntax where the value or variable provided to the function and the rounded value is returned as a result.

``Math.round(val)``
• val is a value or variable which will be rounded to the upper or lower integer value.

## Math.round() Function Examples

Below you can find different examples about the Math.round() function.

``````Math.round(1);
// 1

Math.round(0);
// 0

Math.round(1.1);
// 1

Math.round(0.1);
// 0

Math.round(1.5);
// 2

Math.round(2.4);
// 2

Math.round(2.6);
// 3

Math.round(-0.4);
// -0

Math.round(-0.5);
// -0

Math.round(-0.6);
// -1

Math.round(-3.6);
// -4

Math.round("2.4");
// 2

Math.round("2.6");
// 3

Math.round("-0.4");
// -0

Math.round("-0.5");
// -0

Math.round("-0.6");
// -1``````

We can see that Math.round(-0.5); is resulted in -0 which is a bit strange but there is no problem. As 0 is not a positive or negative number preceding 0 with + or – are the same thing. You can also see that strings can be rounded if their characters converted into numbers.

## Math.round() Function For Negative Values

Rounding positive numbers and understanding the rounding operating about positive numbers are very easy to understand. But negative numbers can be a bit confusing. Actually it is very clear that negative numbers will be rounded to the higher values. For example, -2 is bigger than -3, and values like -2.5, -2.3 will be rounded into the -2 where values like -2.6 or -2.8 will be rounded into the -3.

``````Math.round(-0.4);
// -0

Math.round(-0.5);
// -0

Math.round(-0.6);
// -1

Math.round(-3.6);
// -4``````

## Math.round() Function Errors

While using the Math.round() function there may be some errors and exceptions. Below you can find some error and exception cases about rounding operation.

• Non-numeric string round operation will result NaN .
• Array more than one integer will result the NaN value as there are multiple input and can not return single result.
• Empty variable will result NaN becuase there is no value to round.
• Empty string will result NaN as there is no number to round.