List vs Map in Java

Question

I didnt get the sense of Maps in Java. When is it recommended to use a Map instead of a List?

thanks in advance,

nohereman

Answer 1

Depends on your performance concerns. A Map more explicitly a HashMap will guarantee O(1) on inserts and removes. A List has at worst O(n) to find an item. So if you would be so kind as to elaborate on what your scenario is we may help more.