ArrayList vs List about 2122-s2

[FYimu]

Hint: ArrayList implements List interface

[calvinseptyanto]

If I am not wrong, List is an interface, and you cannot instantiate an interface. That's why you need some implementation, in this case, prof uses ArrayList (under List interface), which is basically a List implemented over an array. Can also check https://www.geeksforgeeks.org/difference-between-list-and-arraylist-in-java/

So from line 16, it will invoke the constructor at line 11, and because of what I mentioned above, there will be no error occurred as ArrayList implements the List interface.

Really sorry if there's a misconception, but if anyone would like to correct me or add something on, please go ahead!

[hwkchia]

Refer to Lecture #1 Slide #15. The code snippet shows that ArrayList (or LinkedList) is a List. More shall be reviewed in Lecture #5. 😃