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Thread: Basic Math Expression Java Problem

  1. #1
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    Unhappy Basic Math Expression Java Problem

    import java.util.*;
    import java.text.*;
    import javax.swing.*;
    class Lab4Part2{
       public static void main (String[] args) {
    		String ex1;
    		Double num, F;
    		final int a=0, b=0;
    		JFrame myWindow=new JFrame();
    		myWindow.setSize(500,400);
    		myWindow.setTitle("Calculator");
    		myWindow.setVisible(true);
    		myWindow.setLocation(600,200);
    		ex1=JOptionPane.showInputDialog(myWindow, "Enter an expression");
    	   F=Double.parseDouble(ex1);
    		num=(a+B);
    		JOptionPane.showMessageDialog(myWindow, "The sum is "+num);
    	}
    }

    I need some help I keep getting an error when I try to run it on JGrasp. I have no clue what I'm doing wrong and for that matter I don't know what I have to do next if I am doing something wrong or not. However I'm trying to create a program where there are one input dialog that asking for the expression in "a+b" form like I would have to input "1+2" and then the second dialog would be a message giving the answer to that 1+2 which would show the message of 3. Thanks for helping.

    PS. I believe the Double.parseDouble is a wrong method in solving this issue and I believe I need to stack but I don't know how.


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Basic Math Expression Java Problem

    I keep getting an error
    Please copy and paste here the full text of the error message.

  3. #3
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    Default Re: Basic Math Expression Java Problem

    What's up with the double thread post? Check back at your other thread, there are many responses.

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    Administrator copeg's Avatar
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    Default Re: Basic Math Expression Java Problem

    Please do not post the same question to the forums more than once. This thread is now locked. Your other thread:
    Basic Math Expression Java Problem

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