Practical 01: Getting Started with Java

This practical will serve as a starting point to getting used to programming in Java. However, all object-oriented programming concepts learnt in this module can also be applied into other object-oriented programming languages like C#, or other languages that have support for it like PHP. Java is only considered a fully object-oriented programming language that's a good starting language to use to learn such concepts.

Tasks

Task 1

Create a program with a new class called FirstJava which produces the following output:

This is my first attempt to
program in Java
It works!

Modify the source code such that it produces the following output:

This is
my first attempt
to program
in Java
    It works!

Task 2

Identify and fix the errors in the following source codes.

Program 1

public class Practical1 {
    public static void main(String[] args) {
        System.out.println('Welcome to Java!);
    }
}

Program 2

public class Test {
    public void main(string[] args) {
        double i = 50.0;
        double k = i + 50.0;
        double j = k + 1;

        System.out.println("j is " + j + " and
            k is " + k);
    }
}

Task 3

Copy and run the following source code.

The expected output should be as follows:

Modify the source code such that it computes the circumference of a circle instead.

Formula:

circumference = 2 * radius * pi

Task 4

Write a Java program to calculate the area and perimeter of a rectangle when the user inputs the width and height using the following formula (display the output in 2 decimal places):

area = width * height

Task 5

Write a program that displays the current GMT time in the format hour:time:second (e.g., 1:45:19).

Task 6

Write a program that converts pounds into kilograms. The program should prompt the user to enter a number in pounds, convert it to kilograms and display the result. Assume 1 pound is equal to 0.454 kilograms.

Task 7

Write a program that converts MYR to USD. The program should prompt the user to enter a double value in MYR, convert it to USD and display the result. Look up online for the latest exchange rate and ensure the currency is displayed in 2 decimal places (as with most currency formats, this rule is a must).

Task 8

Write a program that reads the subtotal and gratuity rate, then computes the gratuity and total. For example, if the user enters 10 for subtotal and 15% for gratuity rate, the program displays $1.50 as gratuity and $11.50 as the total.