In programming, a "return" statement is like a way for a function to say, "Here is my answer," and it helps the program know what to do next. Let's see a simple C++ program that returns 0 and discuss further:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello World!\n";
return 0; // return statement
}
When the main part of the program finishes, it uses a "return" statement to tell the operating system that everything went well, which is shown by the number 0. But if something went wrong, it can use a different number to let the operating system know there was a problem.
However, for the main part of the program, if we forget to use the "return" statement, it's okay because the program will assume everything went well and use the number 0 by default. But for other functions, we always need to use "return" to tell the program what answer to give back. The program can't guess what answer to give on its own.
In simple terms, a "return" statement helps functions communicate their results, and it's necessary for most functions, but the main part of the program has a special rule where it can work without using "return" and still assume everything is okay.