floor, floorl

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Header File

math.h

Category

Math Routines

Prototype

double floor(double x);

long double floorl(long double x);

Description

Rounds down.

floor finds the largest integer not greater than x.

floorl is the long double version; it takes a long double argument and returns a long double result.

Return Value

floor returns the integer found as a double. floorl returns the integer found as a long double.

Example

#include <math.h>
#include <stdio.h>

int main(void)
{
  double number = 123.54;
  double down, up;

  down = floor(number);
  up = ceil(number);

  printf("original number     %5.2lf\n", number);
  printf("number rounded down %5.2lf\n", down);
  printf("number rounded up   %5.2lf\n", up);

  return 0;
}

Portability

	POSIX	Win32	ANSI C	ANSI C++
floor	+	+	+	+
floorl		+	+	+