CODEWITHSUNDEEP
javainputstaticapplettextfield
Bob
Bob

Reputation: 59

Use One TextField to Input multiple data in Java

Im trying to make a program to calculate my average. But i only want to use one TextField for input. Any suggestions?

I tried to make it so when the button changes, it assigns the number to the variable. but it doesnt seem to work.

Also, Java made me assign the variables to 0...i don't know why... but whatever i asign to the variables manually is what is used to calculate the final grade.

this is what i have so far...

public class FinalApplet extends Applet implements ActionListener
{
    private TextField gradeField, finalField;
    private Button enter;

    public void init()
    {
        gradeField = new TextField(8);
        gradeField.addActionListener(this);
        add(gradeField);

        enter = new Button("Enter MP1 Grade");
        enter.addActionListener(this);
        add(enter);

        finalField = new TextField(8);
        finalField.addActionListener(this);
        add(finalField);
    }

    public void actionPerformed(ActionEvent e)
    {
        double mp1 = 0;
        double mp2 = 0;
        double exam1 = 0;
        double mp3 = 0;
        double mp4 = 0;
        double exam2 = 0;
        double finalGrade = 0;
        char letterGrade;
        //if (e.getSource() == gradeField || e.getSource() == enter)

            if (enter.getLabel() == "Enter MP1 Grade")
            {
                mp1 = Double.parseDouble(gradeField.getText());
                enter.setLabel("Enter MP2 Grade");
            }
            else if (enter.getLabel() == "Enter MP2 Grade")
            {
                mp2 = Double.parseDouble(gradeField.getText());
                enter.setLabel("Enter Exam1 Grade");
            }
            else if (enter.getLabel() == "Enter Exam1 Grade")
            {
                exam1 = Double.parseDouble(gradeField.getText());
                enter.setLabel("Enter MP3 Grade");
            }
            else if (enter.getLabel() == "Enter MP3 Grade")
            {
                mp3 = Double.parseDouble(gradeField.getText());
                enter.setLabel("Enter MP4 Grade");
            }
            else if (enter.getLabel() == "Enter MP4 Grade")
            {
                mp4 = Double.parseDouble(gradeField.getText());
                enter.setLabel("Enter Exam2 Grade");
            }
            else if (enter.getLabel() == "Enter Exam2 Grade")
            {
                exam2 = Double.parseDouble(gradeField.getText());
                enter.setLabel("Calculate Final Grade");
            }
            else if (enter.getLabel() == "Calculate Final Grade")
            {
                finalGrade = Math1.calcAverage(mp1, mp2, exam1, mp3, mp4, exam2);
                letterGrade = Math1.getLetter(finalGrade);
                finalField.setText(letterGrade + " - " + finalGrade);
                enter.setLabel("Enter MP1 Grade");
            }

    }
}

public class Math1
{       
    public static double calcAverage(double mp1, double mp2, double exam1, double mp3, double mp4, double exam2)
    {
        double finalGrade;

        finalGrade = (mp1 * .2) + (mp2 * .2) + (exam1 * .1) + (mp3 * .2) + (mp4 * .2) + (exam2 * .1);

        return finalGrade;
    }

    public static char getLetter(double finalGrade)
    {
        if (finalGrade >= 89.5)
            return 'A';
        else if (finalGrade >= 79.5 && finalGrade < 89.5)
            return 'B';
        else if (finalGrade >= 69.5 && finalGrade < 79.5)
            return 'C';
        else if (finalGrade >= 59.5 && finalGrade < 69.5)
            return 'D';
        else
            return 'F';
    }    
}

Upvotes: 0

Views: 2711

Answers (1)

Peeyush
Peeyush

Reputation: 432

You have defined variables as local variables to method 'actionPerformed' . Local variables are initialized every time method is called. You can defined them as global variables to solve. Read More here

package self.edu.stackoverflow;

import java.applet.Applet;
import java.awt.Button;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class StaticFinal extends Applet implements ActionListener {
private TextField gradeField, finalField;
private Button enter;

double mp1 = 0;
double mp2 = 0;
double exam1 = 0;
double mp3 = 0;
double mp4 = 0;
double exam2 = 0;
double finalGrade = 0;
char letterGrade;

public void init() {
    gradeField = new TextField(8);
    gradeField.addActionListener(this);
    add(gradeField);

    enter = new Button("Enter MP1 Grade");
    enter.addActionListener(this);
    add(enter);

    finalField = new TextField(8);
    finalField.addActionListener(this);
    add(finalField);
}

public void actionPerformed(ActionEvent e) {

    // if (e.getSource() == gradeField || e.getSource() == enter)

    if (enter.getLabel() == "Enter MP1 Grade") {
        mp1 = Double.parseDouble(gradeField.getText());
        enter.setLabel("Enter MP2 Grade");
    } else if (enter.getLabel() == "Enter MP2 Grade") {
        mp2 = Double.parseDouble(gradeField.getText());
        enter.setLabel("Enter Exam1 Grade");
    } else if (enter.getLabel() == "Enter Exam1 Grade") {
        exam1 = Double.parseDouble(gradeField.getText());
        enter.setLabel("Enter MP3 Grade");
    } else if (enter.getLabel() == "Enter MP3 Grade") {
        mp3 = Double.parseDouble(gradeField.getText());
        enter.setLabel("Enter MP4 Grade");
    } else if (enter.getLabel() == "Enter MP4 Grade") {
        mp4 = Double.parseDouble(gradeField.getText());
        enter.setLabel("Enter Exam2 Grade");
    } else if (enter.getLabel() == "Enter Exam2 Grade") {
        exam2 = Double.parseDouble(gradeField.getText());
        enter.setLabel("Calculate Final Grade");
    } else if (enter.getLabel() == "Calculate Final Grade") {
        finalGrade = Math1.calcAverage(mp1, mp2, exam1, mp3, mp4, exam2);
        letterGrade = Math1.getLetter(finalGrade);
        finalField.setText(letterGrade + " - " + finalGrade);
        enter.setLabel("Enter MP1 Grade");
    }

}

}

class Math1 { public static double calcAverage(double mp1, double mp2, double exam1, double mp3, double mp4, double exam2) { double finalGrade;

    finalGrade = (mp1 * .2) + (mp2 * .2) + (exam1 * .1) + (mp3 * .2)
            + (mp4 * .2) + (exam2 * .1);

    return finalGrade;
}

public static char getLetter(double finalGrade) {
    if (finalGrade >= 89.5)
        return 'A';
    else if (finalGrade >= 79.5 && finalGrade < 89.5)
        return 'B';
    else if (finalGrade >= 69.5 && finalGrade < 79.5)
        return 'C';
    else if (finalGrade >= 59.5 && finalGrade < 69.5)
        return 'D';
    else
        return 'F';
}

}

Upvotes: 1

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