char switch statement

**jmarsh56** · 05-03-2006

i am trying to write a switch statement that displays whether ch is a vowel, a digit, or something else. i got it to display it as a vowel or something else but the digit part is killing me. this is what i have:

Code:

#include <iostream>
using std::cout;
using std::cin;

int main() {

  char ch;

  //prompt user
  cout << "Enter an character: ";

  cin >> ch;

  //print out the common part of the message here to save typing
  cout << "You entered ";

  switch( ch ) {

      case 'A': case 'E': case 'I': case 'O': case 'U':
	  case 'a': case 'e': case 'i': case 'o': case 'u':
		cout << "a vowel.\n";
	  // it's a vowel, process accordingly
	  break;

	  case ch 0 - 9:            //>= '0' && ch <= '9':
		  cout << "a digit.\n";

	default:
		cout << "something else.\n";
		break;
}  

    

  return 0;

}

i am lost any help would be great thanks

**hk_mp5kpdw** · 05-03-2006

If you are stuck on using a switch to do this you'd need to use:

Code:

case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
    cout << "a digit.\n";
    break;

... similar to what you did with the vowels part.

**SlyMaelstrom** · 05-03-2006

Excuse my confusion, but I don't understand how you did the vowel part properly, yet decided to try some random garbage for the digits that resembles nothing you'd see in a switch statement.

Anyway, as mp5, said.

**jmarsh56** · 05-03-2006

there is no way of adding just one case for all of the digits? i know u can do it with a if - else statement but i have to do it as a switch statement. thanks

**SlyMaelstrom** · 05-03-2006

No, there is no way. Switch statements are case by case.

**jmarsh56** · 05-03-2006

thanks, and i just put the cases across instead of down that is why it looks like that. either way it works.

**whiteflags** · 05-03-2006

I'd recommend using an if/else statement for this instead of switch if only because there would be less typing and it wouldn't look as silly.

**Bench82** · 05-03-2006

If you have a range of values that you wish to pass to a case statement, one way is to create a helper function which will boil down the user's input into a single value representing the range of input values. eg,

Code:

int findCategory(char c)
{ 
    vector<string> lookup;
    lookup.push_back("aeiouAEIOU");
    lookup.push_back("1234567890");
    lookup.push_back("bcdfghjklmnpqrstvwxzyBCDFGHJKLMNPQRSTVWXYZ");

    // Code to search through the lookup table
}

Your findCategory() function could contain a lookup table, such as the vector<string> in the above example, with each entry containing all valid inputs for each input range. It should be fairly trivial to search each entry for a match. (or return an "error" value if no match is found)

Code:

switch( findCategory(input) )
{
case 0:
    cout << "Vowel";
    break;
case 1:
    cout << "Number";
    break;
case 2:
    cout << "Consonant";
    break;
default:
    cout << "Error";
}

So, all possible values at position 0 in the vector might be vowels.. then all possible values at position 1 in the vector might be numbers.. etc.

you can improve readability of the switch statement with this method by using an enum instead of "magic" numbers, but that's not essential.

Thread: char switch statement

Thread Tools

Search Thread

Display

char switch statement

Similar Threads

Seg Fault in Compare Function

code condensing

Passing structures... I can't get it right.

simulate Grep command in Unix using C

Strings are V important...