Variable block scope : block scope variable « Language Basics « C++ Tutorial

1. C++ Tutorial
2. Language Basics
3. block scope variable

#include <iostream>
using std::cout;
using std::endl;

int main() {
  int count1 = 10;
  int count3 = 50;

  cout << endl << "Value of outer count1 = " << count1;

  {
    int count1 = 20;
    int count2 = 30;
    cout << endl << "Value of inner count1 = " << count1;
    count1 += 3;
    count3 += count2;
  }

  cout << endl
       << "Value of outer count1 = " << count1
       << endl
       << "Value of outer count3 = " << count3;

  cout << endl;
  return 0;
}

Value of outer count1 = 10
Value of inner count1 = 20
Value of outer count1 = 10
Value of outer count3 = 80