/* switch statement.
a multiway if/branch.
Lots of syntax: 4 keywords (switch, case, break, default)

 switch (expression) { //Expr usually a variable or method call
                       //that evaluates to an integer or char only.
    case constant:        //case values must be constants, not variables.
	//integral (int and char only). Not double, not string.
	stmts   //The first case value that matches the expr, 
	        //its stmts executed.
	break;   // terminates the switch.  
	         //Else will fall thru to next case's stmts
    case constant:
       stmts
       break;
    case constant:
    case constant:             // either of two values
      stmts
      break;
  // can have as many cases as needed
    default:    // optional.  Catch-all, will execute if none 
        	//of the cases matched
      stmts
   }   //end of switch

switch has limited use: selecting one of a few integral values.
Any switch statement can be turned into cascaded else if structure
(but not vice versa).
*/

//simple calculator example
import java.awt.*;
import javax.swing.*;

public class SwitchTest extends JApplet {     

    public static void main(String[] argv) {
    //public void init() {

	String input;
	input = JOptionPane.showInputDialog( null, 
					     "1. Addition\n"+
					     "2. Subtraction\n"+
					     "3. Multiplication\n"+
					     "4. Division\n");
	int choice;
	choice = Integer.parseInt(input);

	input = JOptionPane.showInputDialog( null, "Enter first number");
	int num1 = Integer.parseInt(input);
	input = JOptionPane.showInputDialog( null, "Enter second number");
	int num2 = Integer.parseInt(input);

	int result;

	switch (choice) {
	case 1: result = num1 + num2;
	    break;
	case 2: result = num1 - num2;
	    break;
	case 3: result = num1 * num2;
	    break;
	case 4: result = num1 / num2;
	    break;
	default: result = 0;
	}

	JOptionPane.showMessageDialog(null, 
				      "Result = "+result);
    }
}