A question

Question

#include <iostream>
using namespace std;

int f(int a){
return ++a;
}

int f(unsigned int a){
return --a;
}

int main() {
cout<<f(5);
return 0;
}

How the compiler make a decision between these two function? Output is 6.

Answer 1

Numbers are handled as integers if not casted into something else. When casting the argument to unsigned into it runs the other function.

Answer 2

cout<<f((unsigned)5)

displays 4

5 in your example defaults to type int, and thus displays 6.

Answer 3

f(5U) is 4 because the U tells the compiler that it's unsigned.