How to add new elements in an array of Objects of Type Figure??

Question

I have a Figure class which has many attributes(variables). Then I create an array of Figures for example
Figs[] figures = new Figure[18];
Later I need to add new Figures to this array at different positions. In my case I have to use the same array.
Is there any way so I can add new Figure elements to this array??
If u have an answer to this question, please share with me.
Thanks
Amit

Answer 1

There are many ways to solve this problem, including creating new arrays as needed, and using System.arraycopy() to move things around. However, the best way is to use ArrayList, as discussed above.
What you cannot do is use toArray() and cast back to String[]. Object[] is not a subclass of String[], even if all of the objects in the Object[] are Strings!
There are two ways to get around this. Create a String[] and copy the Object[] into it with System.arraycopy, or the easy way, which is to use the toArray(Object[]) method. It allows you to specify by example the array class you wish returned. If the array is large enough, it will populate the array directly, otherwise it will create a new one of the same base class. That means any of the following approaches will work, the final decision is mostly a matter of style:
    // create a zero length array to pass as an exemplar
    public final static String STRING_ARRAY_TYPE[]  new String[0];
    String s[] = (String[]) a.toArray(STRING_ARRAY_TYPE);Or:
    String t[] = new String[a.size()];
    a.toArray(t);Or:
    String t[] = a.toArray(new String[a.size()]);;I prefer the first approach generally, and it avoids any race conditions between the evaluation of the ArrayList size and the toArray; however, since ArrayList methods are not synchronized, you probably should do some synchronizing of your own.
Hope this helps.