在线文档教程
C
数值 | Numerics

islessequal

islessequal

Defined in header
#define islessequal(x, y) /* implementation defined */(since C99)

Determines if the floating point number x is less than or equal to the floating-point number y, without setting floating-point exceptions.

Parameters

x-floating point value
y-floating point value

Return value

Nonzero integral value if x <= y, ​0​ otherwise.

Notes

The built-in operator<= for floating-point numbers may raise FE_INVALID if one or both of the arguments is NaN. This function is a "quiet" version of operator<=.

Example

#include <stdio.h> #include <math.h> int main(void) { printf("islessequal(2.0,1.0) = %d\n", islessequal(2.0,1.0) printf("islessequal(1.0,2.0) = %d\n", islessequal(1.0,2.0) printf("islessequal(1.0,1.0) = %d\n", islessequal(1.0,1.0) printf("islessequal(INFINITY,1.0) = %d\n", islessequal(INFINITY,1.0) printf("islessequal(1.0,NAN) = %d\n", islessequal(1.0,NAN) return 0; }

Possible output:

islessequal(2.0,1.0) = 0 islessequal(1.0,2.0) = 1 islessequal(1.0,1.0) = 1 islessequal(INFINITY,1.0) = 0 islessequal(1.0,NAN) = 0

References

  • C11 standard (ISO/IEC 9899:2011):

See also

isgreaterequal (C99)checks if the first floating-point argument is greater or equal than the second (function)

| C++ documentation for islessequal |

© cppreference.com

Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.

http://en.cppreference.com/w/c/numeric/math/islessequal