Help with Switch Statements

[GigaBatz]

I'm working on combining two programs I've already created. Problem is, I need to use switch statements in it. I understand what they do, but I'm confused on where to add them.

#include <file1.h> 
#include <file2.h> 

void mainmenu() 
{ 
string ans; 
cout << "1\tGenerate a Namecard\n2\tCalculate the Volume of a Cone\n3\tExit\n"; 
cin >> ans; 

case 1: case P: case p: 
printNameCard(); 
case 2: case C: case c: 
PrintConeVolume(); 
Else if (ans == "0, E, or e")
main3 ();
return 0; 
} 

I'm fairly certain I'm close to finishing this, if not for my incompetence with switch statements. Any help would be greatly appreciated.

[Sanction]

Here is a simple switch statement I made... if your combining 2x switch statements make sure they use the same "test" variable type.. for example mine uses char..

switch example: http://www.cplusplus.com/doc/tutorial/control/

#include <iostream>
#include <string>
using namespace std;

int main()
{
	char test = 'x';
	
	cout << "Please Enter a single char: 'a'" << endl;
	cin >> test;

	switch (test)
	{
	case 'a':
		cout << "case a: " << endl;
		break;
	case 'A':
		cout << "case A: " << endl;
		break;
	default :
		cout << "this is the default case statement" << endl;
		break;
	}



	system("PAUSE");
	return 0;
}

[GigaBatz]

Okay, but I'm still not entirely sure how to fit that into my current program.

#include <iostream>
#include <string>
#include <file1.h> 
#include <file2.h> 
using namespace std;
void mainmenu() 
{ 
  string ans; 
       char test = 'x'
       cout << "1\tGenerate a Namecard\n2\tCalculate the Volume of a Cone\n3\tExit\n"; 
       cin >> test; 
       
       switch (test)
	{
	case '1':
		cout << "case a: " << endl;
		break;
	case '2':
		cout << "case A: " << endl;
		break;
	default :
		cout << "this is the default case statement" << endl;
		break;
	}

return 0; 
} 

Is it supposed to look something like this?

[admkrk]

switch() works the same way as if/else if statements. You cannot use a string as an argument with a switch(), though. The else/if else and switch() do exactly the same thing in this example:

int item;

cout << "Select a menu item: ";
cin >> item;

// else / if else
if(item == 1)
	cout << "You chose 1";
else if(item == 2)
	cout << "You chose 2";
// ...
else
	cout << "That was not an option";

// switch()
switch(item)
{
case 1:
	cout << "You chose 1";
	break;
case 2:
	cout << "You chose 2";
	break;
// ...
default:
	cout << "That was not an option";
}

If you want to use a string as an argument, you can only use the if/else if method. If you change it to an int or char, you can use either one.

[amannv2]

this might help you..

#include <iostream.h> 

void main() 
{ 
string ans; 
cout << "1\tGenerate a Namecard\n2\tCalculate the Volume of a Cone\n3\tExit\n"; 
cin >> ans; 
switch(ans)
{
case 1: case P: case p: 
            printNameCard(); 
case 2: case C: case c: 
            PrintConeVolume(); 
case 3: exit(1);
default: cout<<"Wrong Choice!;
}
getch();
}  

[TheIdeasMan]

@amannv2

Some problems with your code:

- It is int main() not void main(). That is in the C++ standard.

- switch only works with int or char, not std::string. So it would work if the variable ans was a char and the P's and C's were single quoted. Without the quotes, the compiler is looking for variables named P for example, but it doesn't exist.

- You are missing the break statements after each case, so execution falls through - not what you want - it might execute both functions.

- If using std::string, you must #include <string>

- It is #include <iostream> not <iostream.h>

- It is std::cout, not cout. Note that using namespace std is bad, but you don't have that either, so lines 5,6,7,15 would cause errors.

[GigaBatz]

Alright, I think it's looking better, but I'm still getting some errors, like "no such directory" for the two files.

#include <iostream>
#include <string>
#include <file1.cpp> 
#include <file2.cpp> 
using namespace std;
void mainmenu() 
{
string char; 
  cout << "1\tGenerate a Namecard\n2\tCalculate the Volume of a Cone\n3\tExit\n"; 
cin >> ans; 
switch(char)
{
case 1: case 'P': case 'p': 
            printNameCard();
            break; 
case 2: case 'C': case 'c': 
            PrintConeVolume();
            break;
case 0: case 'E': case 'e': exit(0);
            break;
default: cout<<"Place Holder";
}
}
	}

return 0; 
} 

Would it be easier to try and directly include their source files in this?

[admkrk]

char is a key word, you cannot use it as a variable. I am not sure what you are trying to do, but see if it works better like this:

char ans;
cout << "1\tGenerate a Namecard\n2\tCalculate the Volume of a Cone\n3\tExit\n";
cin >> ans;

switch(ans)
{
//...
}

You also cannot have a mixture of int and char, ans can only be one or the other.

case 1:

// or

case 'P':
case 'p':

[GigaBatz]

I decided to do an overhaul of the code, and this is what I came up with:

#include <iostream>
#include <iomanip>
#include <sstream>
#include <string>
 
using namespace std;

const string UNIVERSITY = "placeholder"; //Define a line of University Name
const string LOCATION = "placeholder "; //Define a line of location
const string NAME = "placeholder"; //Define a line of first and last name
const string DEPARTMENT = "placeholder"; //Define a line of department

int main(int argc, char **argv)
{
    int choice;

    cout << fixed << showpoint << setprecision(2) << endl;
    cout << "This program can calculate volume of a cone, "
         << "or print a name card." << endl;
    cout << "Main Menu: " <<endl;
    cout << "1: Print a name card." << endl;
    cout << "2: Calculate the volume of a cone." << endl;
    cout << "0: Exit the Program" << endl;
    cin >> choice;
    cout << endl;

    while (choice != 0)
    {
        switch (choice)
        {
        case 1: 
                stringstream stream;
    string s;
 
    for(int i=0; i<60; i++)
        stream<<"*";
 
    stream<<"\n";
    stream<<"*"<<UNIVERSITY<<" "<<LOCATION<<"*\n*\n*\n";
    stream<<NAME<<"*\n*\n";
    stream<<DEPARTMENT<<"*\n*\n";
 
    for(int i=0; i<60; i++)
        stream<<"*";
 
    stream<<"\n";
    s = stream.str();
    cout<<s;
    system ("PAUSE");
            break;

        case 2:
float r, h, v;
float pi = 3.14159;
r = 5.8;
h = 6.3;

cout << "What is the Radius?";
cin >> r;

cout << "What is the Height?";
cin >>  h;

 v = (1.0/3.0) * pi * (r*r) * h;
 
 	cout << "The volume of the cone is\n\n " << v << "\n";

system ("PAUSE");
            break;
        default:
            cout << "Invalid choice!" << endl;
        }

        cout << "Main Menu: " <<endl;
        cout << "1: Print a name card" << endl;
        cout << "2: Calculate the volume of a cone." << endl;
        cout << "0: Exit the program." << endl;
        cin >> choice;
        cout << endl;
    }

    return 0;
 }

There only seem to be minor errors throughout, but I don't quite understand what the compiler's saying.

In function `int main(int, char**)':
56 jump to case label
37 crosses initialization of `std::string s'
36 crosses initialization of `std::stringstream stream'
74 jump to case label
58 crosses initialization of `float pi'
37 crosses initialization of `std::string s'
36 crosses initialization of `std::stringstream stream'
56 [Warning] destructor needed for `s'
56 [Warning] where case label appears here
56 [Warning] (enclose actions of previous case statements requiring destructors in their own scope.)
74 [Warning] destructor needed for `s'
74 [Warning] where case label appears here

These are all the errors it has. As usual, any help would be greatly appreciated.

[LendraDwi]

http://stackoverflow.com/questions/5685471/error-jump-to-case-label look here

[GigaBatz]

Alright, it works great now!
Thanks!