foo not called in main Why it needs input ?

Question

#include <iostream>
using namespace std;

int foo(int bar){
cin>>bar;
cout<<bar;
}

int main() {
// foo(0);
return 0;
}

Answer 1

When we use "int foo(int bar){return 0;}" , it means whenever we have to call "foo()" it needs to be passed with a integer value in it , like "foo(54)".
If you want to insert value of "bar" from user(at runtime" you can use this one.
#include <iostream>
using namespace std;

int foo(){
int bar;
cin>>bar;
cout<<bar;
return 0;
}

int main() {
foo();
return 0;
}

Answer 2

Just Curious to know.. what is foo?

Answer 3

it's weird that it's commented out... but the input would allow you to set a different default value before user input every time you call the function but it does seam useless here. I might be missing something.