Maths

Power

> 10**2
100

Or use the more verbose power function.

> Math.pow(10, 2)
100

Round

> Math.round(1234.567)
1235

> Math.round(1234.123)
1234

Unfortunately, passing extra parameters does not set the precision level.

> Math.round(1234.123, 2)
1234

So you need to do this - multiple by a value, round then divide by the value. Here we use 100, using 10 (base) to the power of 2 (precision level).

> Math.round(1234.123 * 100) / 100
1234.12
> Math.round(1234.123 * 10**2) / 10**2
1234.12

As a function:

function round(value, precision = 0) {
  const multiplier = 10 ** precision;
  return Math.round(value * multiplier) / multiplier;
}

Usage:

round(1234.123, 2)
1234.12
> round(1234.12, 1)
1234.1
> round(1234.12)
1234

fround

Convert from 64-bit to 32-bit precision.

See Math.fround in Mozilla docs.

The Math.fround() function returns the nearest 32-bit single precision float representation of a Number.

Ceiling

Round up the value.

> Math.ceil(2.3)
3

A negative value will round towards zero.

> Math.ceil(-1.1)
-1

Floor

Round down the value.

> Math.floor(2.3)
2

A negative value will round away from zero.

> Math.ceil(-1.1)
-2