Thread: problem with object-oriented

This is a bowling score calculation program.

prof. said make this much more object-oriented but i hav no idea how

so, plz help me T.T

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Code:

#include <iostream>

using namespace std;

class game {
public:
	int gamescore; //store the game score
	int ball_1[12]; //1st ball
	int ball_2[12]; //2nd ball
	int e_ball; //bonus of 10th frame

	void init(); 
	void input(); 
	void calc(); 
	void showthescoreboard(); 
};

void game::init() {
	for(int i = 0; i < 12; i++) {
		ball_1[i] = 0;
		ball_2[i] = 0;
	}
	e_ball = 0;
}

void game::input() { //enter the pins you get
	cout << "Enter the number of the pins you throw down" << endl << endl;
	for(int i = 1; i < 10; i++) {
		cout << "FRAME  " << i << endl;
		cout << "1st ball: ";
		cin >> ball_1[i];

		if(ball_1[i] == 10) { //strike
			cout << "STRIKE!!" << endl;
			cout << endl;
			ball_2[i] = 0;
		}

		else if(ball_1[i] < 10) {
			cout << "2nd ball: ";
			cin >> ball_2[i];

			if(ball_1[i]+ball_2[i] == 10) { //spare
			}

			else if(ball_1[i]+ball_2[i] > 10) {
				cout << "ERROR!!" << endl;
				i--;
			}
			cout << endl;
		}

		else {
			cout << "ERROR!!" << endl;
			cout << endl;
			i--;
		}
	}

	cout << "FRAME  " << 10 << endl;

	while(1) { 
		cout << "1st ball: ";
		cin >> ball_1[10];

		if(ball_1[10] == 10) {
			cout << "STRIKE!!" << endl;
			cout << endl;
			cout << "2nd ball: ";
			cin >> ball_2[10];

			if(ball_2[10] == 10) { //bonus
				cout << "STRIKE!!" << endl;
				cout << endl;
				cout << "3rd ball: ";
				cin >> e_ball;

				if(e_ball == 10) {
					cout << "STRIKE!!" << endl;
					cout << endl;

					break;
				}

				else if(e_ball < 10) {
					break;
				}

				else {
					cout << "ERROR!!" << endl;
					cout << endl;
				}
			}

			else if(ball_2[10] < 10) {
				break;
			}

			else {
				cout << "ERROR!!" << endl;
				cout << endl;
			}
		}


		else if(ball_1[10] < 10) {
			cout << "2nd ball: ";
			cin >> ball_2[10];

			if(ball_1[10]+ball_2[10] == 10) { //bonus ball
				cout << "3rd ball: ";
				cin >> e_ball;

				if(e_ball == 10) {
					cout << "STRIKE!!" << endl;
					cout << endl;

					break;
				}

				else if(e_ball < 10) {
					break;
				}

				else {
					cout << "ERROR!!" << endl;
					cout << endl;
				}
			}

			else if(ball_1[10]+ball_2[10] < 10) {
				e_ball = 0;

				break;
			}

			else {
				cout << "ERROR!!" << endl;
				cout << endl;
			}
		}

		else {
			cout << "ERROR!!" << endl;
			cout << endl;
		}
	}
}

void game::calc() { //calculator
	int i = 0;
	for(i = 1; i < 11; i++) {
		if(i == 10) { //calculate 10th frame
			gamescore += ball_1[10] + ball_2[10] + e_ball;
		}
		else {
			if(ball_1[i] == 10) { //STRIKE
				if(ball_1[i+1] == 10 && ball_1[i+2] == 10) { //turkey
					gamescore += 30;
				}
				else if(ball_1[i+1] == 10 && ball_1[i+2] != 10) { //double
					gamescore += 20 + ball_1[i+2];
				}
				else { //else
					gamescore += 10 + ball_1[i+1] + ball_2[i+1];
				}
			}
			else if (ball_1[i] < 10 && ball_1[i]+ball_2[i] == 10) {
				gamescore += 10 + ball_1[i+1];
			}
			else {
				gamescore += ball_1[i] + ball_2[i];
			}
		}
	}
}

void game::showthescoreboard() {
	cout << "Your total score is " << gamescore << endl;
}

int main(void) {
	game play = {0};
	cout << "Bowling Score" << endl << endl;
	play.init();
	play.input();
	play.calc();
	play.showthescoreboard();

	return 0; 
}

Also, game::init appears to be essentially a constructor, so perhaps you should make that into a constructor instead of a member function.

I agree with C_ntua that the code could be split into multiple objects, and some of your code that currently repeats several times (e.g. "if(ball == 10) STRIKE") could then be simplified.

--
Mats

One thing you should do is not use that bad smilie
And if you love coding rewriting the code shouldn't be a problem, since it ain't that long :P

thanks for the answer,

then,, how can I split the code??

I'm so newb. please help me T.T

How about we turn the tide here?

• How would you split the code up?
• What objects do you see in the current code?
• Describe to us what you have in mind to do in order to make this code more object oriented.

If you can't think in terms of objects our help would just get you through one assignment which wouldn't help you learn anything. This question actually applies to any object oriented language which in my opinion makes it a good question. And this is a common task you will be doing should you pursue a career in programming. Refactoring existing code is definitely applicable in the real world.

Think of classes as objects, and think of your current code as a series of instructions that manipulates certain objects.
Like in Tic-tac-toe, you place Pieces (an object) on a board (another object).