Rounding in C

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Section 18.9 Rounding in C

C supports several functions to help with rounding (such as rounding up, rounding down, just rounding, etc). You need to

#include <math.h>

in order to use them. Here are some of the functions at your disposal:

Table 18.1. Rounding Functions in C

Function	Prototype	Description
`floor()`	`double floor(double x);`	Returns the nearest integer which is less than or equal to the argument passed to this function.
`round()`	`double round (double x);`	Returns the nearest integer value of the argument passed to this function.
`lround()`	`long lround (double x);`	Returns the nearest integer value of the argument passed to this function.
`ceil()`	`double ceil (double x);`	Returns the nearest integer value which is greater than or equal to the argument passed to this function.

Activity 18.4.

Why might it be useful to have both a round() and an lround() function?

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