Switch Doesn't Work

[Netdoggie77]

When I run my functions menu1(), menu2(), menu3(), and menu4() by themselves they run fine. When I call them in in Switch, menu2() and menu4() don't work. I've tried suggestions from other threads and they still don't work.

Here's my code:

  #include <iostream>
//#include <sstream>
//#include <istream>
#include <string>
#include<string.h>
#include <stdio.h>
#include <ctype.h>
using namespace std;

//Function Prototypes
void menu1();
void decToBin(long int);
void menu2();
void sizeErr(string);
void zeroOneErr(string);
void binToDec(string);
void menu3();
void decToHex(int);
void menu4();
void sizeHexErr(char [20]);
void hexError(char [20]);
void hexToDec(char [20]);

// Function decimal to binary
void decToBin(long int n)
{
    // array
    long int binNum[100];

    // counter
    int i = 0;
    while (n > 0) {

        // storing binary in array
        binNum[i] = n % 2;
        n = n / 2;
        i++;
    }

    //display
    for (int j = i - 1; j >= 0; j--)
        cout << binNum[j];
}

//Function decimal to binary: accept input and error check
void menu1()
{
	long int n = 0;
		cout << "Enter a Positive Decimal number and I'll convert it to Binary. --> ";
		cin >> n;
		cout << endl;
		while(n <= 0)
		{
			cout << "Please enter a Number Greater Than Zero and I'll convert it to Binary. --> ";
			cin >> n;
			cout << endl;
		}
		decToBin(n);
}

// Function convert binary to decimal
void binToDec(string n)
{
    string num = n;
    int dec_val = 0;

    // Initialize base
    int base = 1;

    //Calulate decimal value
    int len = num.length();
    for (int i=len-1;i>=0;i--)
    {
        if (num[i] == '1')
            dec_val += base;
        base = base * 2;
    }
    cout << dec_val << endl;
}

//Function error check binary to decimal: entry other than zero or one
void zeroOneErr(string cnum)
{
	bool counter = true;
	int len = cnum.length();

	//Check for zeroes and ones
	for(int i = 0; i <= len -1; i++ )
		{
			if(cnum[i] != '0' && cnum[i] != '1')
			counter = false;
		}
	if(counter == false)
		{
			counter = true;
			cout << "\nYou didn't enter all zeroes or ones. ";
			menu2();
		}
		else
		{
			binToDec(cnum);
		}
}

//Function error check binary to decimal: greater than 8 chars
void sizeErr(string cnum)
{
	int len = cnum.length();
	while(len >= 9)
	{
		cout  << endl << "Your number was longer than 8 characters, Enter a Binary number no longer than 8 characters and I'll convert it to Decimal. -->";
		getline(cin, cnum);
		len = cnum.length();
	}
	zeroOneErr(cnum);
}

void menu2()
{
	string cnum;
	cout  << "Enter a Binary number no longer than 8 characters and I'll convert it to Decimal. --> ";
	getline(cin, cnum);
	sizeErr(cnum);
}

// function to convert decimal to hexadecimal
void decToHex(int n)
{
    // char array to store hexadecimal number
    char hexNum[100];

    // counter for hex number array
    int i = 0;
    while(n!=0)
    {
        // store remainder
        int temp  = 0;

        temp = n % 16;

        // check if temp < 10
        if(temp < 10)
        {
            hexNum[i] = temp + 48;
            i++;
        }
        else
        {
            hexNum[i] = temp + 55;
            i++;
        }

        n = n/16;
    }

    // print hex array
    for(int j=i-1; j>=0; j--)
        cout << hexNum[j];
}

void menu3()
{
	int num = -1;
	cout << "Enter a Positive Decimal number and I'll convert it to Hexadecimal. --> " << endl;
	cin >> num;
	while (num <= 0)
	{
		cout << "Your number is not positive. Enter a Positive Decimal number and I'll convert it to Hexadecimal. --> " << endl;
		cin.ignore();
		cin >> num;
	}
	decToHex(num);
}

// Function to convert hex to decimal
void hexToDec(char hexVal[])
{
    int len = strlen(hexVal);

    // Initialize base
    int base = 1;

    int dec_val = 0;

    // Loop through array, last first
    for (int i=len-1; i>=0; i--)
    {
        // Add to decimal value, 0-9
        if (hexVal[i]>='0' && hexVal[i]<='9')
        {
            dec_val += (hexVal[i] - 48)*base;

            // increase to next higher power
            base = base * 16;
        }

        // add to decimal value, a-f
        else if (hexVal[i]>='A' && hexVal[i]<='F')
        {
            dec_val += (hexVal[i] - 55)*base;

            // increase to next higher power
            base = base*16;
        }
    }
    //Display decimal value accumulated in dec_val
    cout << dec_val << endl;
}

void hexError(char hexVal[])
{
	bool counter = true;
	int len = strlen(hexVal);

	//Run toupper() and assign values to array
	for(int i=0; i < len; i++)
	{
		hexVal[i] = toupper(hexVal[i]);
	}

	for (int i=0; i < len; i++)
	{
		if ((hexVal[i]>='0' && hexVal[i]<='9') || (hexVal[i]>='A' && hexVal[i]<='F'))
		{
		}
		else
		{
			counter = false;
		}
	}
	if(counter == false)
	{
		counter = true;
		cout << "\nYou entered characters that aren't hexadecimal. ";
		menu4();
	}
	else
	{
		hexToDec(hexVal);
	}
}

void sizeHexErr(char hexVal[])
{
	int len = strlen(hexVal);
	while(len >= 5)
	{
		cout << "\nYour number was longer than 4 characters, please enter a Hexadecimal number no longer than 4 characters and I'll convert it to Decimal --> ";
		cin.getline(hexVal, 20);
		len = strlen(hexVal);
	}
	hexError(hexVal);
}

void menu4()
{
	char hexNum[20];
	cout << "Enter a Hexadecimal number no longer than 4 characters and I'll convert it to Decimal. --> " << endl;
	cin.getline(hexNum, 20);
	sizeHexErr(hexNum);
}

int main()
{
	int choice;

	//Constants for menu choice
	const int dec_to_bin = 1;
	const int bin_to_dec = 2;
	const int dec_to_hex = 3;
	const int hex_to_dec = 4;
	const int end = 9;

do
{
	//Display menu and get a choice
	cout << "\n\nEnter 1, 2, 3, 4 or 9 to exit --> \n\n";
	cout << "1. Decimal to Binary\n";
	cout << "2. Binary to Decimal\n";
	cout << "3. Decimal to Hex\n";
	cout << "4. Hex to Decimal\n";
	cout << "9. Quit\n\n";

	cin >> choice;

	switch (choice)
	{
		case dec_to_bin :
		{
			menu1();
			break;
		}
		case bin_to_dec :
		{
			menu2();
			break;
		}
		case dec_to_hex :
		{
			menu3();
			break;
		}
		case hex_to_dec :
		{
			menu4();
			break;
		}
		case end :
		{
			break;
		}
		default  :
		{
			cout << "\nYour entry was invalid.\n";
		}
	}
} while (choice != 9);

	//menu1();

	//menu2();

	//menu3();

	//menu4();

	return 0;
}

[lastchance]

It's nothing to do with switch. You are mixing >> with getline and they don't work the same way: the first leaves the newline marker in the input, the latter removes it.

Change your input to
cin >> choice; cin.ignore( 1000, '\n' );
and you will clear the newline char before the getline call in menu2() just picks up a blank end of line.

[zapshe]

You mean they go to the functions but then keeps going without stopping for you to input, right?


Here:

		switch (choice)
		{
		case dec_to_bin:
		{
			menu1();
			break;
		}
		case bin_to_dec:
		{
			cin.get();
			menu2();
			break;
		}
		case dec_to_hex:
		{
			menu3();
			break;
		}
		case hex_to_dec:
		{
			cin.get();
			menu4();
			break;
		}
		case end:
		{
			break;
		}
		default:
		{
			cout << "\nYour entry was invalid.\n";
		}
		}

You're leaving an '\n' in the buffer, getline in menu2() and menu4() sees it and assumes you just pressed enter. cin.get() will gobble it up.