24.02.26.md (894B)
1 # 24/02/26 2 3 - you can use an ArrayList in java (linked list sorta?) 4 - ArrayList is the implementation of `List` (interface) in java, which is an extension of a `Collection` in java 5 - ArrayList is part of `java.util` 6 - `List names = new ArrayList();` 7 - we can see it is of type `List`, as `List` is an interface 8 - we can limit the type of a List to a single type via `List<String> names = new ArrayList<>();` 9 - `List` has the following methods 10 - `void add(Obj o)` appends element 11 - `int size()` gets the size 12 - `void set(int index, Obj o)` sets element at 13 - Since `ArrayList` is an instate of `List`, you can create it via `ArrayList l = new ArrayList()` 14 - It cant store privative data types, only objects, so you will need to put primitives into an object (boxing) 15 16 - The `Collections` class is a static class containing methods to operate on a `Collection`, such as `List`