Question

Calculator = 0.01 Calculate . Add O subtract O Multiply ODvide uttons on the right determine the operation that is performed on the numbers. For example, the following image shows values 12 and 3 are entered in the ion in selected. When the Calculate button is pressed, the result of the addition operation is shown after the equal sign ( In this example, the result is 1 Calculator 12 .15.01 Calculate | ⓔAdd subtract。Multiply O Divide g images show the result of multiplication, subtraction and division operations. Please note that the operation symbol that is shown between the text fielo at is selected by the radio buttons. For example, when multiplication operation is selected, the symbol between the text fields is an x', for subtraction the operation the symbol is a 画calculator 9.0 Calculate AddSubtract Multiply Divide 12 Calculator 36.0 Calculate Add SubtractMultiply Divide 12 Calculator -4.0 Calculate | O Add O subtract O Multiply . Divide

Answer 1

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

// Calculator.java

import java.awt.FlowLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.ButtonGroup;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JRadioButton;

import javax.swing.JTextField;

public class Calculator extends JFrame implements ActionListener {

      // declaring needed UI components

      private JTextField op1, op2;

      private JLabel operator, resultLabel;

      private JButton calculate;

      private JRadioButton addBtn, subBtn, mulBtn, divBtn;

      // constructor initializing GUI

      public Calculator() {

            // will exit on close

            setDefaultCloseOperation(EXIT_ON_CLOSE);

            // initializing text fields for operands and labels for operator and

            // result

            op1 = new JTextField(10);

            operator = new JLabel("+");

            op2 = new JTextField(10);

            resultLabel = new JLabel("0.0");

            // initializing calculate button

            calculate = new JButton("Calculate");

            // initializing radio buttons

            addBtn = new JRadioButton("Add");

            subBtn = new JRadioButton("Subtract");

            mulBtn = new JRadioButton("Multiply");

            divBtn = new JRadioButton("Divide");

            // creating a button group and adding all radio buttons to it, so that

            // only one can be selected at a time

            ButtonGroup group = new ButtonGroup();

            group.add(addBtn);

            group.add(subBtn);

            group.add(mulBtn);

            group.add(divBtn);

            // selecting add button by default

            addBtn.setSelected(true);

            // using flow layout

            setLayout(new FlowLayout());

            // adding each component in order

            add(op1);

            add(operator);

            add(op2);

            add(new JLabel(" = "));

            add(resultLabel);

            add(calculate);

            add(addBtn);

            add(subBtn);

            add(mulBtn);

            add(divBtn);

            // setting window size and title, displaying

            setSize(800, 100);

            setTitle("Calculator");

            setVisible(true);

            // addig action listeners to the buttons

            calculate.addActionListener(this);

            addBtn.addActionListener(this);

            subBtn.addActionListener(this);

            mulBtn.addActionListener(this);

            divBtn.addActionListener(this);

      }

      public static void main(String[] args) {

            // invoking the constructor

            new Calculator();

      }

      @Override

      public void actionPerformed(ActionEvent e) {

            // finding source of action

            if (e.getSource().equals(calculate)) {

                  // calculate btn is pressed

                  try {

                        // fetching values, performing operation and displaying the

                        // result

                        double num1 = Double.parseDouble(op1.getText());

                        double num2 = Double.parseDouble(op2.getText());

                        double result = 0;

                        if (addBtn.isSelected()) {

                              result = num1 + num2;

                        } else if (subBtn.isSelected()) {

                              result = num1 - num2;

                        } else if (mulBtn.isSelected()) {

                              result = num1 * num2;

                        } else if (divBtn.isSelected()) {

                              result = num1 / num2;

                        }

                        resultLabel.setText("" + result);

                  } catch (Exception ex) {

                        resultLabel.setText("Invalid!");

                  }

            } else {

                  // a radio button is clicked, updating operator label text

                  if (addBtn.isSelected()) {

                        operator.setText("+");

                  } else if (subBtn.isSelected()) {

                        operator.setText("-");

                  } else if (mulBtn.isSelected()) {

                        operator.setText("x");

                  } else if (divBtn.isSelected()) {

                        operator.setText("/");

                  }

            }

      }

}

/*OUTPUT*/

의 Calculator 1.0625 CalculateAdd SubtractMultiply Divide 14.4 15.3