Why do some people use the List base class to instantiate a new ArrayList?

Question

I keep coming across code where people instantiate a new ArrayList and assign it to the List interface, like this:

List names = new ArrayList&l         


        

Answer 1

To decouple your code from a specific implementation of the interface.

This also helps you to move to another implementation of the List interface in the future.

For example -

You have List names = new ArrayList(); later on you decide that you should have used some other implementation of the List interface, say LinkedList so you would just change it to List names = new LinkedList(); and nothing breaks.