1. Programming II (CS300) Chapter 02: Using Objects Java ArrayList Class
Mouna KACEM
Spring 2019

2. Java ArrayList Class Java ArrayList Class in Java.util package
uses a dynamic array for storing a set of elements
inherits AbstractList class and implements List interface
Main Properties
Java ArrayList class can contain duplicate elements
Java ArrayList class maintains insertion order
Java ArrayList allows random access
The dynamic array works at the index basis
Iterable
Collection
List
AbstractList
ArrayList
extends
implements

3. Java ArrayList Class Constructors
ArrayList list1 = new ArrayList(); //creating an empty ArrayList
ArrayList<String> list2 = new ArrayList<String>(); //creating an empty ArrayList of elements of type String
the type of elements is specified in angular braces
ArrayList list2 is forced to have only specified type of objects in it (here String).
Adding another type of object, results in a compile time error
ArrayList(Collection c)
build an array list that is initialized with the elements of the collection c.
ArrayList(int capacity)
build an array list that has the specified initial capacity.

4. Java ArrayList Class Main Methods (1) boolean add(Object o)
used to append the specified element to the end of a list.
void add(int index, Object element)
insert the specified element at the specified position index in a list.
boolean addAll(Collection c)
append all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collection's iterator.
boolean addAll(int index, Collection c)
used to insert all of the elements in the specified collection into this list, starting at the specified position.

5. Java ArrayList Class Main Methods (2) int indexOf(Object o)
used to return the index in this list of the first occurrence of the specified element, or -1 if the List does not contain this element.
int lastIndexOf(Object o)
return the index in this list of the last occurrence of the specified element, or -1 if the list does not contain this element.

6. Java ArrayList Class Main Methods(3) void clear() Object[] toArray()
remove all of the elements from this list.
Object[] toArray()
used to return an array containing all of the elements in this list in the correct order.
Object clone()
used to return a shallow copy of an ArrayList.