Using references and C++ array.

cpsc120_for_loop_with_reference.cc

// Gist https://gist.github.com/7323b58b786d7db312a39ab8b0373413

#include <array>
#include <iostream>
#include <string>

int main(int argc, char const* argv[]) {
  std::array<int, 5> my_array{11, 12, 13, 14, 15};
  // Does not change the values in the array
  std::cout << "Showing the arrat contents.\n";
  for (int number : my_array) {
    std::cout << number << "\n";
    number = 42;
  }
  // Show the contents of the array to prove there was no change
  std::cout << "Showing the array contents and nothing has changed.\n";
  for (int number : my_array) {
    std::cout << number << "\n";
  }
  // Using a reference, change the values in the array
  std::cout << "Showing the array contents and changing the values.\n";
  for (int& number : my_array) {
    std::cout << number << "\n";
    number = 42;
  }
  // The values are now changed.
  std::cout << "The values have all changed.\n";
  for (int number : my_array) {
    std::cout << number << "\n";
  }
  return 0;
}