#include using namespace std; int main() { /* Pointers can be used in cases when it is necessary to perform some actions with elements of the array, but the original array must also be preserved. In these cases we use an array of pointers, then after the actions with the elements a new array is created, and the original array does not change. Let's check this by swapping the values of the first and last elements of the array. */ int arr [5] = {0, 1, 2, 3, 4}; // Declare the array int *p [5]; // Declare the array of the pointers int *tmp; // Declare the temporary variable for swapping for (int i = 0; i < 5; i++){ p [i] = &arr [i]; } // Save the addresses of arr elements // in the array of the pointers cout << "Original array" << endl; for (int i = 0; i < 5; i++){ cout << arr [i] << " "; } // Outputs all the elements of the array cout << endl << endl; cout << "Swapping..." << endl << endl; /* Swap the values of the first and last elements of the array */ tmp = p [0]; // Assign the value of the first element // to the temporary variable p [0] = p [4]; // Assign the value of the last element // to the first element p [4] = tmp; // Assign the value of the temporary variable // to the last element /* Check the new array */ cout << "New array" << endl; for (int i = 0; i < 5; i++){ cout << *p [i] << " "; } // Outputs all the elements of the new array cout << endl << endl; /* Check the original array */ cout << "Original array was not changed" << endl; for (int i = 0; i < 5; i++){ cout << arr [i] << " "; } // Outputs all the elements of the original array // We made sure that the original array did not change return 0; }

Pointers and Arrays #4.3 [C++]