Working with Arrays of Objects with Java and NetBeans IDE

In my previous article, we saw how to work with method parameters along with arrays.  Before dealing with arrays of objects, I would like to cover the concept of method overloading in Java.  If you are already familiar with this concept, you can skip this section.

A set of methods sharing the same name with a difference in parameters (return values are not considered) can be called overloading methods.  Please be aware that Java (at the time of this writing) does not support any “parameters with default values.” Other major languages like C++ already support this. To achieve this type of scenario, you may still need to use the concept of overloading.  Let us go through the code first.

Now, open your previous application (or download it from my previous articles) and open “MyCalc.java.”  Modify your code so that it looks something like the following:

  public class MyCalc {

    int x=0;
    int y=0;

    /** Creates a new instance of MyCalc */
    public MyCalc() {
    }

    public void setValues(int p) {
        x = y = p;
    }

    public void setValues(int m, int n) {
        x = m;
        y = n;
    }

    public void setValues(MyCalc c) {
        x = c.x;
        y = c.y;
    }

    public int getSum() {
        int z;
        z = x + y;
        return z;
    }
  }

Now, go back to the frame “test.java.”  Double click on it to open and finally double click on the button to open source view.  Within the source view, modify your “buttonActionPerformed” in such a way that it looks like the following:

  private void btnShowActionPerformed(java.awt.event.ActionEvent evt) {
  // TODO add your handling code here:
        MyCalc obj1 = new MyCalc();
        MyCalc obj2 = new MyCalc();
        obj1.setValues(10,20);
        obj2.setValues(obj1);

        int r;
        r = obj1.getSum();
        this.lblMsg.setText("Sum = " + String.valueOf(r));

        r = obj2.getSum();
        this.lblMsg2.setText("Sum = " + String.valueOf(r));

    }

The next section will explain all of the above code.