stupid "E" in calculator

[2o2]

if i square 8, and get 64, then square that and get 4096, i then square 4096, and get "1.6777216E7" why is the E there already? is there any way to make it so that it does appear that soon, like on the windows calculator, with the windows calculator i have to press the x2 button 7 times to get the e, not only 3 times like on my calculator. Would i have to replace the doubles, and change it to something else, or is there a way to write a double to a jtextfield without having to convert it to a string first?

import java.lang.Math;
import javax.swing.*; 
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.StringSelection;
import java.awt.*;
import java.awt.Toolkit;
//import random shit
public class Main
{
private JPanel MainPanel = new JPanel(); // panel holds the button grid
public static JPanel screenPanel;
public static JFrame frame;
public static JTextField screen;
public static JMenu menu;
public static JMenu edit;
public static JMenu view;
public static JMenuBar menuBar;
public static JMenuItem exit = new JMenuItem("Exit");
public static JMenuItem about = new JMenuItem("About");
public static JMenuItem copy = new JMenuItem("Copy");
public static JCheckBoxMenuItem advanced = new JCheckBoxMenuItem("Advanced");
public static JCheckBoxMenuItem simple = new JCheckBoxMenuItem("Simple");
public static JPanel advancedButtons;
public static JButton log;
public static JButton pi;
public static JButton cube;
public static JButton square;
public static JButton sin;
public static JButton cos;
public static JButton tan;
public static JButton insin;
public static JButton incos;
public static JButton intan;
public static ButtonListener buttonListener;
//{"x²", "sin", "cos", "tan"},
//all the menu items, panels, and the frame

//numbers that allow calc to work
int operation = 0;
double secondnum1;
double firstnum1;
double oppAnswer = 0;
String firstNum;
String writeAnswer;
String secondNum;
double   secondParse;
double   firstParse;
boolean options = true;

  String[][] buttonStrings = // use these Strings to create a JButton grid
  {
  	{"CE", "\u221A", "1/x", "inv"},
      {"7", "8", "9", "/"},
      {"4", "5", "6", "*"},
      {"1", "2", "3", "-"},
      {"0", ".", "=", "+"},
      
  };
  public Main()
  {
    int rowLength = buttonStrings.length;
    int colLength = buttonStrings[0].length;
    MainPanel.setLayout(new GridLayout(rowLength, colLength));
    MainPanel.setSize(200,200);
    buttonListener = new ButtonListener(); // create our ActionListener
    for (int row = 0; row < rowLength; row++)
    {
      for (int col = 0; col < colLength; col++)
      {
        // for each String in the array, create a button that holds the string
        String buttonString = buttonStrings[row][col];
        JButton button = new JButton(buttonString); // this button here
        button.addActionListener(buttonListener); // add the listener
        MainPanel.add(button); // and add it to the panel
      }
    }
        Main.about.addActionListener(new MenuActionListener());
        Main.advanced.addActionListener(new MenuActionListener());
        Main.simple.addActionListener(new MenuActionListener());
        Main.exit.addActionListener(new MenuActionListener());
        Main.copy.addActionListener(new MenuActionListener());
  }
 
 
 
 class MenuActionListener implements ActionListener {
  public void actionPerformed(ActionEvent e) {
    if ((e.getActionCommand().equals("About")) && (options == true)){
    	JOptionPane.showMessageDialog(null, "Java calculator created by Isaac Flaum");
    	options = false;
    }
    if ((e.getActionCommand().equals("Advanced"))){
    	advancedButtons.setVisible(true);
        advanced.setSelected(true);
        simple.setSelected(false);
     frame.pack();
   	 frame.setLocationRelativeTo(null);
    frame.setVisible(true);
    	
    }
     if ((e.getActionCommand().equals("Simple"))){
    	advancedButtons.setVisible(false);
        advanced.setSelected(false);
        simple.setSelected(true);
     frame.pack();	
    }
   
    if ((e.getActionCommand().equals("Copy"))){
  	String s = screen.getText();
StringSelection ss = new StringSelection(s);
Clipboard systemClipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
systemClipboard.setContents(ss,ss);
 }
 
                        
    if ((e.getActionCommand().equals("Exit"))){
  	System.exit(0);
 }        
			
        
}
    

    
  }
  public JComponent getComponent()
  {
    return MainPanel;
  }
  
  // here's the button listener class that of course implements action listener
  private class ButtonListener implements ActionListener
  {
    public void actionPerformed(ActionEvent e)
    {
    	options = true;
    	String screentext = screen.getText();
        // we can easily extract the String held by the button pressed 
        String actionCommand = e.getActionCommand(); // here's the string
            if (actionCommand == "0"){
                screen.setText(screentext + "0");
      	 
      }
            if (actionCommand == "1"){
                 screen.setText(screentext + "1");
      	 
      }
            if (actionCommand == "2"){
                 screen.setText(screentext + "2");
      	 
      }
            if (actionCommand == "3"){
                 screen.setText(screentext + "3");
      	 
      }
            if (actionCommand == "4"){
                 screen.setText(screentext + "4");
      	 
      } 
             if (actionCommand == "5"){
                screen.setText(screentext + "5");
      	 
      }
            if (actionCommand == "6"){
                 screen.setText(screentext + "6");
         
      }
            if (actionCommand == "7"){
                 screen.setText(screentext + "7");
      	 
      }
            if (actionCommand == "8"){
                 screen.setText(screentext + "8");
      	 
      }
            if (actionCommand == "9"){
                 screen.setText(screentext + "9");
      	 
      }
            if (actionCommand == "*"){
                 firstNum = screen.getText();
                 operation = 1;
                 screen.setText("");
      }
            if (actionCommand == "/"){
                firstNum = screen.getText();
                operation = 2;
                screen.setText("");
      	 
      }
            if (actionCommand == "+"){
                 firstNum = screen.getText();
                 operation = 3;
                screen.setText("");
      }
            if (actionCommand == "-"){
                firstNum = screen.getText();
                operation = 4;
                 screen.setText("");
      }
            if (actionCommand == "."){
                screen.setText(screentext + ".");
      }
      		if (actionCommand == "CE"){
      			screen.setText("");
      			secondNum = "";
      			firstNum = "";
      			firstParse = 0;
      			secondParse = 0;
      			operation = 0;
      			writeAnswer = "";
      		}
      		if (actionCommand == "1/x"){
      			secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = 1 / secondParse;
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);
      		}
      		if (actionCommand == "inv"){
      			secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = -1 * secondParse;
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);
      		}
      
      		if (actionCommand == "\u221A"){
      		    secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			if (secondParse < 0){
      				screen.setText("Error");
      			}
      			else{
      				oppAnswer = Math.sqrt(secondParse);
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      			}
      			
      		}
                 if (actionCommand == "x²"){
                        secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = secondParse * secondParse;
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
      		//3.1415926535897932384626433832795 = pi
                if (actionCommand == "sin"){
                        secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = Math.sin(secondParse);
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
      		  if (actionCommand == "asin"){
                        secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = Math.asin(secondParse);
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
                if (actionCommand == "cos"){
                        secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = Math.cos(secondParse);
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
      		if (actionCommand == "acos"){
                        secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = Math.acos(secondParse);
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
                if (actionCommand == "tan"){
                        secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = Math.tan(secondParse);
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
      		//³
      		if (actionCommand == "x³"){
                secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = secondParse * secondParse * secondParse;
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
      		if (actionCommand == "atan"){
                        secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = Math.atan(secondParse);
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
      		if (actionCommand == "log"){
                        secondNum = screen.getText();
      			secondParse = Double.parseDouble(secondNum);
      			oppAnswer = Math.log10(secondParse);
      			
      			writeAnswer = Double.toString(oppAnswer);
      			screen.setText(writeAnswer);	
      		}
      		if (actionCommand == "\u03C0"){
      			screen.setText("3.1415926535897932384626433832795");	
      		}
                if (actionCommand == "="){
			secondNum  = screen.getText();
			screen.setText("");
			firstParse = Double.parseDouble(firstNum);
                        secondParse = Double.parseDouble(secondNum);
			if(operation == 1){
                            oppAnswer = firstParse * secondParse;
                            writeAnswer = Double.toString(oppAnswer);
                            screen.setText(writeAnswer);
			}	
			if(operation == 2){
				oppAnswer = firstParse / secondParse;
				writeAnswer = Double.toString(oppAnswer);
				screen.setText(writeAnswer);
			}
			if(operation == 4){
				oppAnswer = firstParse - secondParse;
				writeAnswer = Double.toString(oppAnswer);
				screen.setText(writeAnswer);
			}
			if(operation == 3){
				oppAnswer = firstParse + secondParse;
				writeAnswer = Double.toString(oppAnswer);
				screen.setText(writeAnswer);
			}
            
      		} 
     
    }
  }

  // this calls our Swing code in a thread-safe manner  
  private static void createAndShowUI()
  {
    Main.frame = new JFrame("Calculator"); 
    frame.setLayout(new BorderLayout());
    frame.getContentPane().add(new Main().getComponent());
    Main.screenPanel = new JPanel(); //panel to hold screen
    Main.screenPanel.setLayout(new GridLayout(2, 1));
    Main.screen = new JTextField(20);
    Main.menu = new JMenu("File");
    Main.view = new JMenu("View");
    Main.menuBar = new JMenuBar();
    Main.edit = new JMenu("Edit");
    edit.add(copy);
   
    menu.add(exit);
    menu.add(about);
    menuBar.add(menu);
    menuBar.add(edit);
    menuBar.add(view);
    view.add(advanced);
   	view.add(simple);
    log = new JButton("Log");
    Main.screenPanel.add(Main.menuBar);
    Main.screenPanel.add(screen);
    frame.add(Main.screenPanel, BorderLayout.NORTH);
    advancedButtons = new JPanel(new GridLayout(5,2)); //pain in the ass gridlayout manager
    log = new JButton("log");
    sin = new JButton("sin");
    insin = new JButton("asin");
    cos = new JButton("cos");
    incos = new JButton("acos");
    tan = new JButton("tan");
    intan = new JButton("atan");
    cube = new JButton("x³");
    pi = new JButton("\u03C0");
    square = new JButton("x²");
    
    advancedButtons.add(log);
    advancedButtons.add(square);
    advancedButtons.add(sin);
    advancedButtons.add(insin);
    advancedButtons.add(cos);
     advancedButtons.add(incos);
    advancedButtons.add(tan);
     advancedButtons.add(intan);
    advancedButtons.add(cube);
    advancedButtons.add(pi);
    sin.addActionListener(Main.buttonListener);
    cos.addActionListener(Main.buttonListener);
    tan.addActionListener(Main.buttonListener);
    insin.addActionListener(Main.buttonListener);
    incos.addActionListener(Main.buttonListener);
    intan.addActionListener(Main.buttonListener);
    log.addActionListener(Main.buttonListener);
    square.addActionListener(Main.buttonListener);
    cube.addActionListener(Main.buttonListener);
    pi.addActionListener(Main.buttonListener);
    sin.setToolTipText("Calculates the Sine of a number");
    cos.setToolTipText("Calculates the Cosine of a number");
    tan.setToolTipText("Calculates the Tangent of a number");
    insin.setToolTipText("Calculates the Inverse Sine of a number");
    incos.setToolTipText("Calculates the Inverse Cosine of a number");
    intan.setToolTipText("Calculates the Inverse Tangent of a number");
    log.setToolTipText("Calculates the Logarithm of a number");
    square.setToolTipText("Squares a number");
    cube.setToolTipText("Cubes a number");
    frame.add(advancedButtons,BorderLayout.EAST);
    advanced.setSelected(false);
    simple.setSelected(true);
    advancedButtons.setVisible(false);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }
	
  public static void main(String[] args)
  {
      try{
      UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
      }
      catch (UnsupportedLookAndFeelException e) {
       // handle exception
    }
    catch (ClassNotFoundException e) {
       // handle exception
    }
    catch (InstantiationException e) {
       // handle exception
    }
    catch (IllegalAccessException e) {
       // handle exception
    }
    java.awt.EventQueue.invokeLater(new Runnable()
    {
      public void run()
      {
        createAndShowUI();
      }
    });
  }
}

[2o2]

and yes, btw i know what the E means

[Eranga]

You can format the string into some fixed number of decimals.

[2o2]

You can format the string into some fixed number of decimals.

how would i go about doing that?

[Eranga]

Read bit more about followings.

NumberFormat (Java 2 Platform SE v1.4.2)

Formatter (Java 2 Platform SE 5.0)