Re: How do you iterate over a List and remove elements?

Patricia Shanahan <>
Fri, 24 Aug 2007 09:37:16 -0700
Manish Pandit wrote:

On Aug 24, 8:51 am, Patricia Shanahan <> wrote:

What is the purpose of the list.contains(obj) pre-check?

My bad..did not realize contains returns a boolean. Been thinking
about this for a while, and I was wondering if it makes sense to use
an array (or another list..a clone) as an intermediatory. I know this
has scalability and performance numbers against it though. Here is a
little snippet:

         ArrayList<Integer> list = new ArrayList<Integer>();
         for(int i=0; i<10; i++){
         //remove all the even numbers
         Integer[] array = new Integer[list.size()];
         for( int i:array ){
             if( i%2==0 ) {
                 list.remove(new Integer(i));

Ofcourse this needs to be synchronized, to make sure the array and the
list do not go out of sync.


What is the advantage of this, compared to the really dumb, simple,
obvious approach using the Iterator remove() method?

      //remove all the even numbers
      Iterator<Integer> it = list.iterator();
        if( % 2 == 0){


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