// Program shows an example of global variables and dynamic memory allocation for uni-dimensional arrays #include using namespace std; // Global variables declaration int *a = nullptr; // Global functions prototype void FillArray(int); void DisplayArray(int); long int SumArray(int); int main() { int aSize; cout << "Please input array length:" << endl; cin >> aSize; // Validate user inputed data if (aSize > 0) { // Allocate memory dynamically for the array try { a = new int[aSize]; FillArray(aSize); DisplayArray(aSize); cout << "Sum of the array elements is: " << SumArray(aSize); // Free the dynamically allocated memory delete [] a; // Reset pointer value to exclude the possibility of a dangling pointer a = nullptr; } catch (bad_alloc &e) { cerr << "The required memory for array could not be allocated! [" << e.what() << "]" << endl; } } else { cout << "Array length needs to be greather than zero!"; } return 0; } // Global functions definition void FillArray(int arrLength) { cout << "Please input data for each element of the array:" << endl; for (int i = 0; i < arrLength; i++) { cout << "a[" << i << "]: "; cin >> a[i]; } } void DisplayArray(int arrLength) { cout << "Elements of the array are:" << endl; for (int i = 0; i < arrLength; i++) { cout << "a[" << i << "] = " << a[i] << ";" << endl; } } long int SumArray(int arrLength) { long int s = 0; for (int i = 0; i < arrLength; i++) { s += a[i]; } return s; }

Global variables and dynamic memory