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The latest version of this topic can be found at fabs, fabsf, fabsl.
Calculates the absolute value of the floating-point argument.
Syntax
double fabs(
double x
);
float fabs(
float x
); // C++ only
long double fabs(
long double x
); // C++ only
float fabsf(
float x
);
long double fabsl(
long double x
);
Parameters
x
Floating-point value.
Return Value
The fabs functions return the absolute value of the argument x. There is no error return.
| Input | SEH Exception | Matherr Exception |
|---|---|---|
| ± QNAN,IND | none | _DOMAIN |
Remarks
C++ allows overloading, so you can call overloads of fabs if you include the <cmath> header. In a C program, fabs always takes and returns a double.
Requirements
| Function | Required C header | Required C++ header |
|---|---|---|
fabs, fabsf, fabsl |
<math.h> | <cmath> or <math.h> |
For additional compatibility information, see Compatibility in the Introduction.
Example
See the example for abs.
See Also
Floating-Point Support
abs, labs, llabs, _abs64
_cabs
labs, llabs