I've managed to output all the ship's location after it make each 10 units movement towards north east using the code above, without putting the 'add 10 coordinates' in a function.Code:#include <iostream> #include <cstdlib> #include <ctime> using namespace std; struct Spaceship; Spaceship move_ship(Spaceship ship); void update_location(Spaceship ship, int &count); Spaceship get_new_ship(Spaceship ship); struct Spaceship { int x_coordinate; int y_coordinate; }; Spaceship get_new_ship() { Spaceship ship; ship.x_coordinate = 0; ship.y_coordinate = 0; return ship; } void update_location(Spaceship ship,int &count) { std::cout << "Ship is now located at (" << ship.x_coordinate << "," << ship.y_coordinate << ")." << endl; if (ship.x_coordinate > 1024 || ship.y_coordinate > 768) { std::cout << "Ship has left the screen. \n"; count = 0; } } int main() { int count = 1; Spaceship ship = get_new_ship(); do{ ship.x_coordinate = ship.x_coordinate + 10; ship.y_coordinate = ship.y_coordinate + 10; update_location(ship,count); } while(count != 0); }

However if I put it this way (put it in the functionSpaceshipmove_ship(),coordinate x and y remains zero. What is wrong with my function? ):

Code:#include <iostream> #include <cstdlib> #include <ctime> using namespace std; struct Spaceship; Spaceship move_ship(Spaceship ship); void update_location(Spaceship ship, int &count); Spaceship get_new_ship(Spaceship ship); struct Spaceship { int x_coordinate; int y_coordinate; }; Spaceship get_new_ship() { Spaceship ship; ship.x_coordinate = 0; ship.y_coordinate = 0; return ship; } Spaceship move_ship(Spaceship ship) { ship.x_coordinate = ship.x_coordinate + 10; ship.y_coordinate = ship.y_coordinate + 10; return ship; } void update_location(Spaceship ship,int &count) { std::cout << "Ship is now located at (" << ship.x_coordinate << "," << ship.y_coordinate << ")." << endl; if (ship.x_coordinate > 1024 || ship.y_coordinate > 768) { std::cout << "Ship has left the screen. \n"; count = 0; } } int main() { int count = 1; Spaceship ship = get_new_ship(); do{ move_ship(ship); update_location(ship,count); } while(count != 0); }