VariableScope

#include <iostream>

using namespace std;

int a = 10;

int main(int argc, char const *argv[])
{
    cout << __LINE__ << "\t" << a << endl;

    for (int i = 0; i < 5; ++i)
    {
        cout << __LINE__ << "\t" << a << endl;
        int a = 3;
        cout << __LINE__ << "\t" << a << endl;
    }

    cout << __LINE__ << "\t" << a << endl;
    int a = 8;

    cout << __LINE__ << "\t" << a << endl;

    if (a > 9) {
        int a = 20;
        cout << __LINE__ << "\t" << a << endl;
    } else {
        int a = 30;
        cout << __LINE__ << "\t" << a << endl;
    }

    cout << __LINE__ << "\t" << a << endl;

    return 0;
}