6.10. Complex Numbers
6.10 Complex Numbers
ISO C99 supports complex floating data types, and as an extension GCC supports them in C90 mode and in C++. GCC also supports complex integer data types which are not part of ISO C99. You can declare complex types using the keyword _Complex
. As an extension, the older GNU keyword __complex__
is also supported.
For example, ‘_Complex double x;
’ declares x
as a variable whose real part and imaginary part are both of type double
. ‘_Complex short int y;
’ declares y
to have real and imaginary parts of type short int
; this is not likely to be useful, but it shows that the set of complex types is complete.
To write a constant with a complex data type, use the suffix ‘i
’ or ‘j
’ (either one; they are equivalent). For