_Complex

 

C

Language

Standard Library

Type support

Dynamic memory management

Error handling

Program utilities

Date and time utilities

Strings library

Algorithms

Numerics

Input/output support

Localization support

Thread support (C11)

Atomic operations (C11)

 

C language

General topics
Preprocessor
Comments
Keywords
Escape sequences
History of C
Flow control
Conditional execution statements
if statement	switch statement
Iteration statements
for loop	while loop do-while loop
Jump statements
continue statement break statement	goto statement return statement
Functions
function declaration
inline specifier
Types
fundamental types pointer types compound types enumeration types	union types function types
Specifiers
cv specifiers
storage-class specifiers
alignas specifier (C99)
function specifiers (C99)
Literals
integer literals character literals floating-point literals	string literals boolean literals(C99)
Expressions
order of evaluation
operators
operator precedence
alternative operators
Utilities
typedef declaration
attributes (C99)
casts
Miscellaneous
Inline assembly

 

Implements a complex-number type.

Keywords

_Complex

Example

Run this code

#include <stdio.h>
 
int main(void)
{
   printf("sizeof(_Complex float)       = %2zu\n", sizeof(_Complex float));
   printf("sizeof(_Complex double)      = %2zu\n", sizeof(_Complex double));
   printf("sizeof(_Complex long double) = %2zu\n", sizeof(_Complex long double));
 
    /* definition, initialization, and printing of _Complex variable */
    _Complex double z, zc;
    __real__ z = 1.0;  __imag__ z = 2.0;
    printf("%.1f%+.1fi\n", __real__ z, __imag__ z);
 
    /* complex assignment */
    zc = z;
 
    /* complex conjugate */
    __imag__ zc = -__imag__ z;
    printf("%.1f%+.1fi\n", __real__ zc, __imag__ zc);
 
    /* complex product */
    /* (a+bi)(a-bi) = a^2 + b^2 */
    z = z*zc;
    printf("%.1f%+.1fi\n", __real__ z, __imag__ z);
 
    return 0;
}

Possible output:

sizeof(_Complex float)       =  8
sizeof(_Complex double)      = 16
sizeof(_Complex long double) = 32
1.0+2.0i
1.0-2.0i
5.0+0.0i