[Code Hoof Set Novice Village 600 Questions] Define a function as a macro

Title link:

Things to solve the problem:

Using macros to define functions is different from normal function definitions,

In the macro definition,

Because it's a text replacement,

So the content of the macro definition is theoretically one line,

But since we're using a macro to define a function,

So put \

at the end of each line

Makes all lines above and below theoretically one line

The return value of the macro-defined function is not realized by the keyword return,

Instead, replace the essence with normal macros,

Just add a variable directly at the end of the function defined by the macro,

That is, write the value to be returned separately

Note the proper use of parentheses

Reference code: