# crealf, creal, creall

< c‎ | numeric‎ | complex

C
 Language Headers Type support Program utilities Variadic function support Error handling Dynamic memory management Date and time utilities Strings library Algorithms Numerics Input/output support Localization support Atomic operations (C11) Thread support (C11) Technical Specifications

Complex number arithmetic
Types and the imaginary constant
Manipulation
 cimag creal carg
Power and exponential functions
Trigonometric functions
Hyperbolic functions

 Defined in header `` float       crealf( float complex z ); (1) (since C99) double      creal( double complex z ); (2) (since C99) long double creall( long double complex z ); (3) (since C99) Defined in header `` #define creal( z ) (4) (since C99)
1-3) Returns the real part of `z`.
4) Type-generic macro: if `z` has type long double complex, long double imaginary, or long double, `creall` is called. If `z` has type float complex, float imaginary, or float, `crealf` is called. If `z` has type double complex, double imaginary, double, or any integer type, `creal` is called.

### Parameters

 z - complex argument

### Return value

The real part of `z`.

This function is fully specified for all possible inputs and is not subject to any errors described in math_errhandling

### Notes

For any complex variable `z`, z == creal(z) + I*cimag(z).

### Example

```#include <stdio.h>
#include <complex.h>

int main(void)
{
double complex z = 1.0 + 2.0*I;
printf("%f%+fi\n", creal(z), cimag(z));
}```

Output:

`1.000000+2.000000i`

### References

• C11 standard (ISO/IEC 9899:2011):
• 7.3.9.6 The creal functions (p: 198-199)
• 7.25 Type-generic math <tgmath.h> (p: 373-375)
• G.7 Type-generic math <tgmath.h> (p: 545)
• C99 standard (ISO/IEC 9899:1999):
• 7.3.9.5 The creal functions (p: 180)
• 7.22 Type-generic math <tgmath.h> (p: 335-337)
• G.7 Type-generic math <tgmath.h> (p: 480)