// This program demonstrates how to dynamically allocate memory to an array at runtime. #include using namespace std; int main() { // Firstly declare an array and assign a null pointer to it. int *arr = nullptr; // Define two variables. The first will get the size of array needed. The second will help us calculate the sum. int arr_size, sum=0; // Place a conditional variable that we will use in our loop to keep the program running. bool condition = true; // Place a variable that will helpnus know the condition our loop will get into. char decision; // Create a do while loop to act as a menu driven platform. do { // Ask the user how many inputs he has. cout << "How many numbers do you want to add: "; // cin object helps us get what he types on the keypad or keyboard. cin >> arr_size; // The code below creates a new array equivalent to hold the data desired by the user arr = new int[arr_size ]; // Next the user is allowed to input his numbers cout << "Enter the numbers to be added:\n"; // The for loop is performing two functions. Firstly, it is helping us collect numbers from the user and allocating them to specified places in the array. Lastly, it is helping us add the numbers being entered each time it iterates. for (int i=0; i>arr[i]; // The code below is adding numbers being collected. sum += arr[i]; } // Finally we can display the sum after succesful iteration using cout whichbis like print to the screen. cout << "The sum is: " << sum << endl; // The code below helps us to empty the array that we created in line 22 delete [] arr; // We hastily assign nullptr to arr to avoid junk or unwanted data. arr = nullptr; // Sum is once again assignes to zero to avoid us getting wrong output in case the user decides to oerform another operation. sum = 0; // Here we ask the user if he wants to perforn another operation. cout << "Would you like to perform another operation (y/n): "; // Cin gets users decision so we can use it to determine whether to re-run the loop or not. cin >> decision; // system(" cls") or system("clear") can be used to wipe during runtime. // The conditional checks the users input. If he input capital or small letter y we have handled the situation. If users input is "y" which means yes it means he wants to do it again otherwise he does not want. if (decision == 'y' || decision == 'Y') condition = true; else condition = false; // While will check whether the decision made was true or false, if it was false the loop stops. If not it continues. }while (condition != false); return 0; } // Do ask if you have queries.

Determing Array Size at Runtime