Language in C 面试题与答案

Question: ceil( ) and floor( )

Answer: The math function ceil( ) takes a double value as an argument. This function finds the smallest possible integer to which the given number can be rounded up. Similarly, floor( ) being a math function, takes a double value as an argument and returns the largest possible integer to which the given double value can be rounded down. The following program demonstrates the use of both the functions.

#include <math.h>
void main( )
{
double no = 1437.23167 ;
double down, up ;

down = floor ( no ) ;
up = ceil ( no ) ;

printf ( "The original number %7.5lfn", no ) ;
printf ( "The number rounded down %7.5lfn", down ) ;
printf ( "The number rounded up %7.5lfn", up ) ;
}

The output of this program would be,
The original number 1437.23167
The number rounded down 1437.00000
The number rounded up 1438.00000