Question

How, if it’s possible, can you call a method from another method’s return?

For example…

class Example {
    public static void main(String[] args) {
        Point t1 = new Point(0,0);
        Point t2 = new Point(0,1);
        ArrayList pointContainer = new ArrayList();
        pointContainer.add(0,t1);
        pointContainer.add(0,t2);    // We now have an ArrayList containing t1 & t2
        System.out.println(pointContainer.get(1).getLocation()); // The problem area
    }
}

In the poorly written example, I’m trying to invoke the getLocation() method (part of java.swing.awt) on index item 1 of pointContainer.

When trying to compile the program, I get the following error…

HW.java:20: error: cannot find symbol
        System.out.println(test.get(1).getLocation());
                                  ^
  symbol:   method getLocation()
  location: class Object

Could someone please help me with this problem.

Answer 1

First, type your ArrayList so that Java can know what objects are coming out of it.

List<Point> pointContainer = new ArrayList<Point>();

Then, any objects you retrieve from that ArrayList will be of type Point, so you can perform operations on them.