Here what's the meaning of cout<<::x

Question

#include <iostream>
using namespace std;
void fun();
int x=1;
int main() {
fun();
return 0;
}

void fun(){
int x=2;
{
int x=3;
cout<<::x;
}
}
output is 1

Answer 1

:: is a scope resolution operator. ::x accesses the value of the global x, instead of the local x in the function.