converting string to number for boolean and if/if else with message boxes

[timtim123]

Hello, I searched around over the last day and although I found multiple threads that helped me understand how the code works and such, I didn't seem to find anything I could directly apply to what I'm working on.

I am trying to get a simple rock, paper, scissors program working with an input dialogue box to enter your choice (this works fine) and then message dialogue boxes for the results (Not working). I understand that you have to convert a string to an int in order to use mathematical equations or Boolean expressions, but I can't seem to get it working with if and if else in the mix. Below is what I'm working with. For now, I'm just trying to get the "Invalid" portion working which I assume I can re-use for the other portions. Everything works fine in the command prompt output, just need to get displays in message boxes ---

import javax.swing.JOptionPane;

public class RockPaperScissors2 {
public static void main(String[] args) {

//Random number for computer choice
int compPick = (int)(Math.random() * 3 );

//Enter user pick
String Choice = JOptionPane.showInputDialog (
"Pick Rock, Paper, or Scissors: (0 = Scissors, 1 = Rock, 2 = Paper): ");


String output = "Computer picks: " + compPick;
JOptionPane.showMessageDialog(null, output);

// Invalid Entry

int Invalid = Integer.parseInt(Invalid);
if (Choice >= 3);
String Invalid = "Invalid Entry";
JOptionPane.showMessageDialog(null, "Invalid");


//Draw result
else if (Choice == compPick)
System.out.println ("Draw");

//Winning results
else if (Choice == 0 && compPick == 2)
System.out.println("Scissors beats Paper. You Win!");

else if (Choice == 1 && compPick == 0)
System.out.println("Rock beats Scissors. You Win!");

else if (Choice == 2 && compPick == 1)
System.out.println("Paper beats Rock. You Win!");

//Losing results
else if (Choice == 0 && compPick == 1)
System.out.println("Scissors loses to Rock. You Lose.");

else if (Choice == 1 && compPick == 2)
System.out.println("Rock loses to Paper. You Lose.");

else if (Choice == 2 && compPick == 0)
System.out.println("Paper loses to Scissors. You Lose.");

}
}

[Eranga]

On the following line, where you define and initialize the variable Invalid?

int Invalid = Integer.parseInt(Invalid);

[Eranga]

And also please use the code tags when you are posting code segments again to the forum. Unformated codes are really hard to read at once.

[timtim123]

Thanks for the reply, unfortunately, I'm not following though. I'm trying to have all of the results display in message boxes. From what I understand, I have to convert the string to a number in order to do this, right? Am I converting the string "Choice" to an int for this to work? Below is the program as it sits currently. All of the outputs are displaying in message boxes up until it gets to the Invalid Entry point and beyond, I guess because this is where the boolean expressions come in and is failing since it isn't converted to an int?

import javax.swing.JOptionPane;

public class RockPaperScissors2 {
public static void main(String[] args) {

//Random number for computer choice
int compPick = (int)(Math.random() * 3 );

//Enter user pick
String Choice = JOptionPane.showInputDialog (
"Pick Rock, Paper, or Scissors: (0 = Scissors, 1 = Rock, 2 = Paper): ");


String output = "Computer picks: " + compPick;
JOptionPane.showMessageDialog(null, output);


// Invalid Entry

if (Choice >= 3)
 	System.out.println ("Invalid Entry");


//Draw result
else if (Choice == compPick)
System.out.println ("Draw");

//Winning results
else if (Choice == 0 && compPick == 2)
System.out.println("Scissors beats Paper. You Win!");

else if (Choice == 1 && compPick == 0)
System.out.println("Rock beats Scissors. You Win!");

else if (Choice == 2 && compPick == 1)
System.out.println("Paper beats Rock. You Win!");

//Losing results
else if (Choice == 0 && compPick == 1)
System.out.println("Scissors loses to Rock. You Lose.");

else if (Choice == 1 && compPick == 2)
System.out.println("Rock loses to Paper. You Lose.");

else if (Choice == 2 && compPick == 0)
System.out.println("Paper loses to Scissors. You Lose.");

}
}

[Eranga]

First of all run the following line of code and see.

JOptionPane.showMessageDialog(null, 1, "Title", JOptionPane.INFORMATION_MESSAGE);
        
JOptionPane.showMessageDialog(null, "One", "Title", JOptionPane.INFORMATION_MESSAGE);

[timtim123]

I don't understand? What am I supposed to do with those two lines? I'm not trying to have anyone write this for me, but any references or examples that can help me out would be appreciated.

I put those two lines in my program and tried to compile and just got a few errors that led to more each time I tried to correct

[Eranga]

I don't understand? What am I supposed to do with those two lines? I'm not trying to have anyone write this for me, but any references or examples that can help me out would be appreciated.

I am not writing code for you. Just give you a guidance. I have not ask you to put those lines into your code and see, just say to run those lines of code and see. Because I want to give an answer to the following question.

I'm trying to have all of the results display in message boxes. From what I understand, I have to convert the string to a number in order to do this, right?

[Eranga]

Initialize a string variable and in each result conditions (if/else if) assign the result into it. Then at the end you can display in a message box. If you pick what I in 5th post, really you don't want to convert the variable into int and so on. Doing that have some advantages, but not necessary.