Not able to remove from an ArrayList [closed]

Answer 1

Try this : It will remove all occurrence of "B" from your List without any loop.

lstStr.removeAll(Collections.singleton("B"));

Answer 2

You can't remove an item from a collection you're iterating over except using Iterator.remove - you'll get a ConcurrentModificationException. So your loop would be something like:

for (Iterator<String> iterator = list.iterator(); iterator.hasNext();) {
    String value = iterator.next();
    if (value.equals("B")) {
        iterator.remove();
    }
}

Of course, you should use removeAll to just remove all items with a specific value - but the above approach is the one to use if you need to remove based on some condition other than simple equality (e.g. "remove all values with a length greater than 5". Another option is to collect all the values to remove in a new collection, and then call removeAll afterwards.

Answer 3

Use the iterator's remove method. It will remove the element from the collection.