Collection



What is Collection?

A collection is an object that represents a group of objects.

Collection interface is the root interface for manipulating a collection of objects.

To Use Java Collection need to import java.util
package


Collection (I)
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   List(I)             Set(I)                 Queue(I)
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+ ArrayList (Class)

+ LinkedList(Class)
+ Vector (Class)
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+ Stack (Class)






Collection (I)
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   List(I)             Set(I)               Queue(I)
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+   +
+ HashSet (Class)   + TreeSet
| (Class)
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+ LinkedHashSet(Class)

Collection (I)
Methods:
 public abstract int size();
  public abstract boolean isEmpty();
  public abstract boolean contains(java.lang.Object);
  public abstract java.util.Iterator<E> iterator();
  public abstract java.lang.Object[] toArray();
  public abstract <T> T[] toArray(T[]);
  public abstract boolean add(E);
  public abstract boolean remove(java.lang.Object);
  public abstract boolean containsAll(java.util.Collection<?>);
  public abstract boolean addAll(java.util.Collection<? extends E>);
  public abstract boolean removeAll(java.util.Collection<?>);
  public abstract boolean retainAll(java.util.Collection<?>);
  public abstract void clear();
 

 List(I)

 void add(int index,E element)

 E get(int index)

 E set(int index,E element)

 int indexOf(Object o)

 int lastIndexOf(Object O)

 ListIterartor <E> listIterator()


ArrayList

+It is dynamically growable in nature.
+Unsunchonized Collection
+We can make it synchronized
        Collections.synchronizedList()

+Stores data in Order/sequential fashion (Unsorted)

+User can access element using index
+allows null value
+allows duplicates

+Can Travese Through Iterator and ListIterartor

+Initail Capacity of ArrayList 10
Automatically Grows CC*3/2

+Constructor

public ArrayList()  //default size 10

public ArrayList(int intialCapcity)

Public ArrayList(Collection C)




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