Help (Beginner)

I need to make a menu in a for or while loop that redisplays the menu after each selection and updates the variable each time. With a switch structure to control the program options.The options of the menu are 1 increment the variable 2 decrement the variable and 3 exit. If someone could help me I would really appreciate it.

uhh, wheee

Code:

---

#include <iostream>
using namespace std;

int main()
{
        int i = 0, choice;
        bool exit = false;

        while(!exit)
        {
                cout << "i = " << i;
                cout << "\n1. increment\n2. decrement\n3. exit\n\n";

                cout << "Choose: ";
                cin >> choice;

                switch(choice)
                {
                case 1:
                        i ++;
                        break;
                case 2:
                        i --;
                        break;
                case 3:
                        exit = true;
                        break;
                }

                cout << endl;
        }

        return 0;
}

---

This is what i have so far

Code:

---

#include <iostream.h>
int main ()
{
int i;
char input;

while (1)
        {
cout <<"\n\n";
cout << "                **** Increment / Decrement ****\n\n";
cout << "                The present value of the internal variable is:"<< i <<endl;endl;
cout << "                (I)ncrement the Internal Variable.\n";
cout << "                (D)ecrement the Internal Variable.\n";
cout << "                (E)xit the program.\n\n";
cout << "        Select==>";
cin >> input;

switch (input)
                {
       
case 'I':
case 'i':
                i ++;
                break;

case 'D':
case 'd':
                i --;
                break;
                }
if (input == 'E' || input == 'e'){break;}
        }
}

---

What do i need to do to fix it. The variable is showing some wierd numbers and its not updating. Its also supposed to start off at 10.

You need to initialize "i" before you can use it properly :D

Code:

---

#include <iostream.h>

int main ()
{
        int i = 10;
        char input;

        while (1)
        {
                cout <<"\n\n";
                cout << "                **** Increment / Decrement ****\n\n";
                cout << "                The present value of the internal variable is:"<< i <<endl << endl;
                cout << "                (I)ncrement the Internal Variable.\n";
                cout << "                (D)ecrement the Internal Variable.\n";
                cout << "                (E)xit the program.\n\n";
                cout << "        Select==>";
                cin >> input;

                switch (input)
                {
                       
                case 'I':
                case 'i':
                                i ++;
                                break;

                case 'D':
                case 'd':
                                i --;
                                break;
                }

                if (input == 'E' || input == 'e')
                        break;
        }

        return 0;
}

---

Dude thanks a lot!!!. Now it says to rewrite it with nested loops so it doesnt redraw unless "i" or "d" is chosen and i need to exit when "e" is chosen. You'd be the coolest ever if you could show me how to do this.

Hmm, that is coming a bit unclear to me, perhaps something like this?

Code:

---

#include <iostream.h>

int main ()
{
        int i = 10;
        char input;
        bool exit = false;

        while (!exit)
        {
                cout <<"\n\n";
                cout << "                **** Increment / Decrement ****\n\n";
                cout << "                The present value of the internal variable is:"<< i <<endl << endl;
                cout << "                (I)ncrement the Internal Variable.\n";
                cout << "                (D)ecrement the Internal Variable.\n";
                cout << "                (E)xit the program.\n\n";

                do
                {
                        cout << "        Select==>";
                        cin >> input;

                        switch (input)
                        {
                               
                        case 'I':
                        case 'i':
                                        i ++;
                                        break;

                        case 'D':
                        case 'd':
                                        i --;
                                        break;
                        case 'e':
                                        exit = true;
                                        break;
                        }
                }
                while(input != 'i' && input != 'd' && input != 'e');
        }

        return 0;
}

---

Thanks so much abrege!!! You probably saved me from failing my programming class.

No problem :D

What is break all about?

In a switch statement, program execution begins at the first case that is successful. Program execution will then continue through the switch statement. break; causes the remaining switch cases to be skipped.

In the example, you can see he has a case for 'i' and 'I', no break; so either will run the block. If he had not put the break at the end of the 'I' block, the program would then have processed the 'd' block and so on.

There are other uses for break; but that is what it is doing there.