3.7 Rounding Operations

The functions ffloor, fceiling, fround, and ftruncate take a floating-point argument and return a floating-point result whose value is a nearby integer. ffloor returns the nearest integer below; fceiling, the nearest integer above; ftruncate, the nearest integer in the direction towards zero; fround, the nearest integer.

function ffloor float

This function rounds float to the next lower integral value, and returns that value as a floating-point number.

function fceiling float

This function rounds float to the next higher integral value, and returns that value as a floating-point number.

function ftruncate float

This function rounds float towards zero to an integral value, and returns that value as a floating-point number.

function fround float

This function rounds float to the nearest integral value, and returns that value as a floating-point number. Rounding a value equidistant between two integers returns the even integer.