Question

(b) Write a class Conversion containing the following methods: (i) constructor: which builds the frame shown on the right side. The frame consists of a text field for inputting a NZD amount, a label with 10 spaces for an equivalent HKD amount, and a button to start the calculation. Declare any necessary attributes in the class and add appropriate action listeners for future use. Copy the class, including import statement(s), as the answers to this part Calculate (ii) actionPerformed : which performs the calculation and puts the result on the label when the button is pressed. You can assume one NZD is equivalent to 5.5 HKD. You can assume a valid realnumber1234 is entered in the textfield. Copy the method as the answers to this part 67.87 Calculate (iii) mainO which creates a Conversion object and sets it visible for testing. Copy the method as 120 the answers to this part

Answer 1

Conversion.java

// import all required classes and interfaces

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JTextField;

// create Conversion class which extends JFrame class

// and implements ActionListener interface

public class Conversion extends JFrame implements ActionListener {

// declare all required components

JLabel l;

JTextField t;

JButton b;

// constructor

public Conversion() {

super(); // calls super class constructor

// intantiate all declated components

l=new JLabel();

t=new JTextField(25);

b=new JButton("Calculate");

// setting bounds to all components

t.setBounds(10,15,100,25);

l.setBounds(110,15,100,25);

b.setBounds(10,40,200,28);

// add components into frame

add(t);

add(l);

add(b);

// setting action listener on button

b.addActionListener(this);

setLayout(null); // set layout as null

setSize(240,120); // set size of the frame

setVisible(true); // make frame visible

}

// override actionPerformed() method

public void actionPerformed(ActionEvent ae)

{

double nzd=Double.parseDouble(t.getText());

double hkd=nzd*5.5;

l.setText(" "+hkd);

}

public static void main(String[] args) {

new Conversion(); // anonymous object

}

}

Output