Symbolic Constant
Each #define line consists of three parts:
The body of a macro can be not only a single numeric value, but also other macros or entire expressions:
main
#include <stdio.h> #define TWO 2 // macros with value. #define RESULT TWO*TWO // TWO is replaced by the number 2. #define PRINT printf("result = %d", RESULT); int main() { PRINT return 0; }
Every time the compiler encounters “TWO”, it will simply substitute its value 2.
The macro is immutable. Once defined, it is a permanent textual substitution within the file or scope where it is defined.
Why do we need this? Why not just use variables?
What is better to use?:
If the value never changes, const is better, because it is safer;
If you need to substitute a simple number or text, you can use a macro.
Create an object macro
add, the body of the macro is an addition operator+.Use a macro to add any two numbers.
Taak
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- Create an object macro
add, the body of the macro is an addition operator+; - Use a macro to add any two numbers.
Oplossing
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