Week 2 Java • 3 min read

To gain more experience with Java, I decided to try to create my own program, using OOP, and this program as a template:

public class HelloObject {
    private String hello;   // instance attribute or variable
    public HelloObject() {  // constructor
        hello = "Hello, World!";
    }
    public String getHello() {  // getter, returns value from inside the object
        return this.hello;  // return String from object
    }
    public static void main(String[] args) {    
        HelloObject ho = new HelloObject(); // Instance of Class (ho) is an Object via "new HelloObject()"
        System.out.println(ho.getHello()); // Object allows reference to public methods and data
    }
}
// IJava activation
HelloObject.main(null);

I decided to make a program to sum all the numbers from 1 to 100 The original code is below:

int sum = 0;
for (int i=1; i<101; i++) {
    sum = sum+i;
}
System.out.println(sum)

And revised code is below:

public class SumObject {
    private int sum;
    public SumObject() {
        sum = 0;
    }
    public int getSum() {
        return sum;
    }
    public void setSum(int s) {
        sum = s;
    }
    public static void main(String[] args) {
        SumObject summer = new SumObject();
        for (int i=1; i<101; i++) {
            int s = summer.getSum();
            summer.setSum(i+s);
        }
        System.out.println(summer.getSum());
    }
}
SumObject.main(null);