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What is the use of a void function if it doesn't return a value? (lemmy.ml)

submitted 3 years ago by the_tech_beast@lemmy.ml to c/cpp@lemmy.ml

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[–] the_tech_beast@lemmy.ml 1 points 3 years ago (1 children)

yes but sum() gives the value 90 in the main function. Why is that?

[–] lunatichacker@lemmy.ml 3 points 3 years ago (1 children)

You're printing s to console not returning it.

[–] the_tech_beast@lemmy.ml 0 points 3 years ago (3 children)

Oh... so cout << and return don't mean the same thing.

[–] tmpod 5 points 3 years ago (1 children)

No. Printing something to the console (pushing something to cout with the << operator) is not the same as returning a value.

Think of returns like what you have in math. When you have a function, let's say

int double(int n) {
    return 2 * n;
}

that returns an int, calling it will "replace" the expression with its result, much like in math. So in this instance, doing 3 + double(2) would be like doing 3 + 4. Math is the same way; if you have a function, f(x) = 2x, doing 3 + f(2) would be the same as doing 3 + 4.

Printing to the console involves doing I/O (input/output), and actually writing a string to a file, which then the terminal can display.

[–] the_tech_beast@lemmy.ml 0 points 3 years ago (1 children)

Thanks this is helpful

[–] tmpod 1 points 3 years ago

Glad to help :3

[–] ChinaNumberOne@lemmy.ml 3 points 3 years ago (2 children)

don't know if you are a beginner to programming in general or c/c++ specifically but it's better to start with c before c++, it's simpler and clearer (than c++) to a beginner

then cout syntax is absolutely horrible and very misleading, use c's printf or, if you can, use fmt, it's super fast and even simpler than c's printf

[–] glibg10b@lemmy.ml 1 points 1 year ago

If you want to learn C++, you should start with C++. Starting with C will form unsafe habits and teach unsafe paradigms that have been replaced by language features or parts of the C++ standard library

it's simpler and clearer (than c++) to a beginner

A language only seems as clear as the tutorial used to teach it. If you think the basics of C++ can be better taught using a C tutorial,. you've been looking at the wrong C++ tutorials. Transitioning from C to C++ will be a confusing process for a beginner

[–] lunatichacker@lemmy.ml 1 points 3 years ago (1 children)

Of course they aren't the same. try to achieve the same output with int sum() instead of void sum() this small exercise will help you understand the difference

[–] the_tech_beast@lemmy.ml 0 points 3 years ago

Yes, thanks for the help