Question

Lets say I have a list like this:

private LinkedList<String> messages = new LinkedList<String>();

When my method gets invoked for the first time there some strings added to this list. And I have also another method in which I need to clear this list from previously added values. To clear it I can use:

messages.clear();

This will remove all the elements from the list. Also I can create a new instance like this:

messages = new LinkedList<String>();

Which way is more proper to clear the list?

Answer 1

It clearly depends upon your need.

If you want to keep reference to your list object instance (as an example if that clear method is called inside a method in which the messages is a parameter, then the call to .clear() is the best solution.

On the other hand, if the list you want to clear is a member field (or a local variable in a method) of the object the current method is a member of, then you can call new LinkedList<String>(); without any trouble.

Notice that, to avoid the first (which I tend to disapprove), i usuall always return obejcts I modify as results from methods modifying them.