JOptionPane Input to int

Question

I am trying to make a JOptionPane get an input and assign it to an int but I am getting some problems with the variable types.

I am trying something like this:

Int ans = (Integer) JOptionPane.showInputDialog(frame,
            "Text",
            JOptionPane.INFORMATION_MESSAGE,
            null,
            null,
            "[sample text to help input]");

But I am getting:

Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot
be cast to java.lang.Integer

Which sounds logical yet, I cannot think of another way to make this happen.

score 9 · Accepted Answer · answered Jun 25 '10 at 19:42

9

Simply use:

int ans = Integer.parseInt( JOptionPane.showInputDialog(frame,
        "Text",
        JOptionPane.INFORMATION_MESSAGE,
        null,
        null,
        "[sample text to help input]"));

You cannot cast a String to an int, but you can convert it using Integer.parseInt(string).

answered Jun 25 '10 at 19:42

jjnguy

136,852
53
295
323

Hmm... it seems I need to also add int ans = Integer.parseInt( JOptionPane.showInputDialog(frame, "Text", JOptionPane.INFORMATION_MESSAGE, null, null, "[sample text to help input]").toString()); – kxk Jun 25 '10 at 19:52
@devil If you use the correct form of `showinputdialog` you won't need to do that. But, you are correct in some cases. – jjnguy Jun 25 '10 at 19:55
I see I see. If I may ask one more thing, is there a way, using a loop maybe, to check if the input given actually is an integer or not? Sth like: ... do { ans = JOptionPane.showInputDialog(...) } until ans = integer ? – kxk Jun 25 '10 at 19:58

score 5 · Answer 2 · answered Jun 25 '10 at 19:43

This because the input that the user inserts into the JOptionPane is a String and it is stored and returned as a String.

Java cannot convert between strings and number by itself, you have to use specific functions, just use:

int ans = Integer.parseInt(JOptionPane.showInputDialog(...))

score 1 · Answer 3 · answered Oct 14 '21 at 04:38

import javax.swing.*;
public class JOptionSample { 
    public static void main(String[] args) {

       String name = JOptionPane.showInputDialog("Enter First integer");

      String name2 = JOptionPane.showInputDialog("Enter second integer");

       JOptionPane.showMessageDialog(null, "The first inputted is 89 and the second 
    integers inputted is 45" );

    int number =Integer.parseInt(JOptionPane.showInputDialog(null, "89+45 = "));

    JOptionPane.showMessageDialog(null, "Question Message", "Title",
   JOptionPane.QUESTION_MESSAGE);

    int option = JOptionPane.showConfirmDialog(null, "Do you want to continue? ");
    JOptionPane.showMessageDialog(null, "Your choice is "+option);

    JOptionPane.showMessageDialog(null, " The sum of the two integers is : 134 ");
}
}

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score 0 · Answer 4 · answered Jun 25 '10 at 21:12

0

Please note that Integer.parseInt throws an NumberFormatException if the passed string doesn't contain a parsable string.

answered Jun 25 '10 at 21:12

Davy Meers

1,758
14
8

score 0 · Answer 5 · edited Apr 06 '16 at 18:13

// sample code for addition using JOptionPane

import javax.swing.JOptionPane;

public class Addition {

    public static void main(String[] args) {

        String firstNumber = JOptionPane.showInputDialog("Input <First Integer>");

        String secondNumber = JOptionPane.showInputDialog("Input <Second Integer>");

        int num1 = Integer.parseInt(firstNumber);
        int num2 = Integer.parseInt(secondNumber);
        int sum = num1 + num2;
        JOptionPane.showMessageDialog(null, "Sum is" + sum, "Sum of two Integers", JOptionPane.PLAIN_MESSAGE);
    }
}

score 0 · Answer 6 · answered Jan 01 '17 at 14:12

0

String String_firstNumber = JOptionPane.showInputDialog("Input  Semisecond");
int Int_firstNumber = Integer.parseInt(firstNumber);

Now your Int_firstnumber contains integer value of String_fristNumber.

hope it helped

answered Jan 01 '17 at 14:12

mubarak baloch

1
1

JOptionPane Input to int

6 Answers6

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