I'm trying to delete an item from the middle of an array of objects, but the code i'm using keeps erroring.

basically, i've tried to split the array into 2 pieces, around the index of the item to be removed, and then join the two pieces back together. However when I use the splice command, i get a ClassCastException.

I thought I was using it right, but clearly not.

here's my code

Code:

//f is the instance to be removed from the array
stem[] arrayP1 = (stem[]) subset(stems,0,f);
stem[] arrayP2 = (stem[]) subset(stems,f);
stems = (stem[]) splice(arrayP1,arrayP2,arrayP1.length);
//stem[] stems = (stem[]) splice(arrayP1,arrayP2,arrayP1.length); doesn't work either...

 

How can I make this work, or is there an easier way to do it all together?

Thanks

Martin

EDIT: thanks for the reply antiplastik, i wrote this without checking if anyone had replied first... I'll see if i can work out ArrayList, I've seen it mentioned elsewhere.


Ok, after a bit of looking round (that I admittedly should have spent longer on before posting originally) i found the concat function.

This avoids the problem of the ClassCast problem, however it seems to do something strange and I can't pin down what's happening. Basically, what I think should happen is that if a particular stem has reached 600, it should remove that from the array, but leave the others. However, on running it, when one reaches that point, they all get deleted.

I presume this has something to do with program flow, but i can't work it out.

Code:

  void update(){
    println(stems.length);
    for (int f=0;f<stems.length;f++){
	
	if (stems[f].rY>600){
	  //we should delete if from the array
	  stem[] arrayP1 = (stem[]) subset(stems,1,f);
	  stem[] arrayP2 = (stem[]) subset(stems,f+1);
	  println(arrayP1.length);
	  println(arrayP2.length);
	  stems = (stem[])concat(arrayP1,arrayP2);
	  println(stems.length);
	  break;
	}
	stems[f].update();
    }
  }
 

Any help would be appreciated.

Thanks
Martin

check out this thread for more info on arrayLists. I've been using them ever since.

You're too kind ;-)

By the way, for those who would like to use ArrayLists to easily remove elements from a list while iterating it (as you did when checking if the value > 600), you can't do that using java.util.ArrayList.remove() method. You must iterate your list with an iterator and use the java.util.Iterator.remove() method, otherwise a Concurrent Modification Exception may be thrown.