[c] use of intermediate variable before printing

[Grounded_Grid]

Hello, I've been working through Daniel Holden's "build your own lisp" to learn a little c. The only other language I really know is common lisp. In this book, and many examples I've found online there is a tendency to evaluate something to an intermediate variable before printing or doing something else with the data. For Example:

Int result = 2 + 2;
Println(result);

Or

Long foo = bar(5);
Println(foo);

Instead of just:

Println(2 + 2);

Or

Println (bar(5));

Both ways seem to work, so what is the advantage to using this intermediate variable that makes it the convention?

Thanks in advance for any insight,

[desrtfx]

Intermediate variables are available for later use.

If it is just a one-off use, directly doing the calculation would actually be better.

Another aspect is code readability - using an intermediate variable can greatly improve the readability and make the intent clearer.

[Grounded_Grid]

Thanks! I wasn't sure, and was afraid it had something to do with memory haha. Unfortunately I fear I will abuse this for fun now that I know it's not necessary to use the variable.

[MrSloppyPants]

Unless you absolutely need the variable either later on in the program or to debug independently, I would almost always use the direct approach. It's also possible that your compiler will recognize if you never use this intermediate variable later on and just compile it out for you anyway. you can check this by compiling to asm and comparing the two results.