Problems with menu

[trannghi7707]

Hello everyone,

I'm new on this forum and I would not come here to ask for help if I'm not desperate. I just learn loop last week and my professor give me a project to create a menu for a math tutor program. The user will then select what do they want to do. The program will seed 2 random numbers from 200 to 999 if the user select addition or subtraction. If the user select division or multiplication, the second number will be seeded again from 0 to 10. Here's my code.

///This program belongs to Nghi Tran
// C.S. M10A Fall 2014- Sec. 71245
// Lab06A: Math Tutor with menu options

#include <iostream>
#include <iomanip>
#include <cstdlib>

using namespace std;

int main()
{	//Introduction to user
	cout << "Welcome to Math Tutor. This program is designed to help student" << endl;
	cout << "to learn how to do basic math such as addition, subtraction,..." << endl;
	cout << endl;

	//Display my name header on the screen
	cout << "******************************" << endl;
	cout << "           Nghi Tran          " << endl;
	cout << "      C.S M10A Fall 2014      " << endl;
	cout << "   Programming Assignment 6   " << endl;
	cout << "   Due Date: Thurs. Oct. 2    " << endl;
	cout << "******************************" << endl;
	cout << endl;

	//Declare variables
	char choice;
	int num1, num2, answer, useranswer, remainder, userremainder;

	//Seed 2 random numbers
	srand(static_cast<unsigned int>(time(0)));
	num1 = rand() % 200 + 800;
	num2 = 1 + rand() % 200;
	
	do
	{
		//Display the menu to user and get user input
		cout << "Select one of the following options" << endl;
		cout << "-----------------------------------------" << endl;
		cout << "1. [A]dd         [+]" << endl;
		cout << "2. [S]ubtract    [-]" << endl;
		cout << "3. [M]ultiply    [x]" << endl;
		cout << "4. [D]ivide      [/]" << endl;
		cout << "5. [Q]uit           " << endl;
		cin >> choice;
		cout << "Your choice is: " << choice << endl;


		//Respond to user's selection
		switch (choice)
			{
			
			case 'A':
			case 'a':
			case '1':
			case '+':
				answer = num1 + num2;
				cout <<""<< num1 << endl;
				cout << "+" << num2 << endl;	
				cout << "-----" << endl;
				cout << "Enter your answer: " << useranswer;
				if (answer == useranswer)
					{
					cout << "Congratulation, Your answer is correct" << endl;
					cout << num1;
					cout << "+" << num2;
					cout << "------" << endl;
					cout << answer;

					}
				else
					{
					cout << "You answer is not correct" << endl;
					cout << "The answer is: " << answer;
					}
				break;
			case 'S':
			case 's':
			case '2':
			case '-':
				answer = num1 - num2;
				cout << num1;
				cout << "-" << num2;
				cout << "------" << endl;
				cout << "Enter your answer: " << useranswer;
				if (answer == useranswer)
					{
					cout << "Congratulation, Your answer is correct" << endl;
					cout << num1;
					cout << "-" << num2;
					cout << "------" << endl;
					cout << answer;
					}
				else
					{
					cout << "You answer is not correct" << endl;
					cout << "The answer is: " << answer;
					}
				break;

			//Seed the second number again
			num2 = 1 + rand() % 10;

			case 'M':
			case 'm':
			case '3':
			case 'x':
				answer = num1 * num2;
				cout << num1;
				cout << "x" << num2;
				cout << "------" << endl;
				cout << "Enter your answer: " << useranswer;
				if (answer == useranswer)
					{
					cout << "Congratulation, Your answer is correct" << endl;
					cout << num1;
					cout << "x" << num2;
					cout << "------" << endl;
					cout << answer;
					}
				else
				{
					cout << "You answer is not correct" << endl;
					cout << "The answer is: " << answer;
				}
				break;

		
			
			case 'D':
			case 'd':
			case '4':
			case '/':
				answer = (num1/num2);
				cout << "        __________" << endl;
				cout << num2 << ")" << num1 << endl;
				cout << "Enter your answer, both the quotient";
				cout << "and the remainder separated by a space: " << endl;
				cin >> useranswer >> remainder;
				if ((useranswer == answer) && (userremainder = remainder))
					{
					cout << "Congratulation, Your answer is correct" << endl;
					cout << "        __________" << endl;
					cout << num2 << ")" << num1 << endl;
					cout << "The answer is: " << answer << "and the remainder is: " << remainder << endl;
					}
				else 
				{
					cout << "Sorry. The correct answer is: " << answer << " and the remainder is: " << remainder << endl;

				}
			case 'Q':
			case 'q':
			case '5':
				cout << "Exiting the program....." << endl;
				break;

			//Validate user's chocie
			default:
				{
					cout << "Please enter a valid choice" << endl;
					cout << "You can enter a number from 1 to 5 or" << endl;
					cout << "A letter corresponding to the calculation that you want to do" << endl;
					cin >> choice;
					cout << "Your choice is: " << choice;
				}


			}

		//Pause the screen
			if (choice != 5)
			{
				cout << endl;
				cin.ignore(80, '\n');
				cout << "Hit the enter key to continue....\n";
				cin.get();
				cout << endl;
			}


	} while (choice != 5);

	return 0;
}

I can compile and run the program but when I enter A or a or 1 or +, it won't do the computation.

Thank you for reading.

[48T7M4Gy]

Your while is selecting on the basis of the numbers 1 and 5 and not the characters '1' and '5'. You also need to check for the other character input possibilities. Quite a long list of or's

[trannghi7707]

Your while is selecting on the basis of the numbers 1 and 5 and not the characters '1' and '5'. You also need to check for the other character input possibilities. Quite a long list of or's

well what I want is if the user select A or a or 1 or +, the addition computation will happen. if it's anything else, the message error will show up. How do I do this ? Is the do-while loop a bad choice ? Should I use for loop instead ?

[48T7M4Gy]

I understood what you are trying to do and there is nothing wrong in principle with giving many options for the same type of calculation. All it does is make a very long test for validating the input. Keep it simple and you don't have such a long list. But there's nothing wrong and there's probably no better way of doing it. You could save a little by using toupper() to get everything into uppercase before the test but that's marginal.

FWIW I would only have 1 option in each case - 1, 2, 3 or 4 but there you go.

There's also nothing wrong with using a while loop. It's better than lots of if's, else's etc.
:-)

[PCrumley48]

use "default" to force the loop back to the menu. If the user has entered a valid choice it will never get to default, so it becomes the fallback option for any incorrect entries.

[trannghi7707]

Thank you kemort and PCrumley.

I follow PCrumley instruction and got rid of that problem. Now i can compile the code but it keep pop up
run-time check failure #3 the variable answer is being used without being initialized.

I updated my code on 1st post

[48T7M4Gy]

I can't get it toreproduce that error on my machine but what it means is you might like to change line 28:

int num1, num2, answer = 0, useranswer = 0, remainder, userremainder;

[trannghi7707]

Thank you kemort for helping me. All problems are solved.