## Operator


The ## operator is used to perform string concatenation in a macro replacement list. For example, if the macro definition:

#define function_like_macro(parameterA,parameterB) parameterA ## parameterB

is called as follows:

function_like_macro(Hello,World)

then the resultant output is HelloWorld. Macros adjacent to the ## operator (in the replacement list ) are not expanded prior to the concatenation. For example, if the macros:

#define concatenate(A,B) A ## B
#define Color Blue
#define Code Heeler

are defined then the expression:

concatenate(Color,Code)

has resultant output ColorCode rather than BlueHeeler.