Macros with arguments

We can also write macros that accept arguments. Here's an example of a macro with an argument:

#define println(X) cout << X << endl;

What this macro will do is every time println("Some value") is encountered in the code, the code on the right-hand side (cout << "Some value" << endl) will be copied and pasted on the console. Notice how the argument between the brackets is copied in the place of X. Say we had the following line of code:

println( "Hello there" )

This will be replaced by the following statement:

cout << "Hello there" << endl;

Macros with arguments are exactly like very short functions. Macros cannot contain any newline characters in them.

Advice – use inline functions instead of macros with arguments

You have to know about how macros with arguments work because you will encounter them in C++ code a lot. Whenever possible, however, many C++ programmers prefer to use inline functions...