Abstract Set

Java Programming Tutorial

About Lesson

Abstract Set

In Java, the AbstractSet class is the part of the Java Collection Framework. The Abstract list is implemented by the collection interface and the Abstract Collection class. The AbstractSet class does not override the AbstractCollection class but can implement equals() and hashCode() method.

Below is the class Hierarchy

abstract-set

Syntax:


public abstract class AbstractSet<E> extends
 AbstractCollection<E>implements Set<E>

Example:


import java.util.*; 
public class AbstractSetDemo1{ 
    public static void main(String[] args) throws 
Exception 
    { 
        try { 
AbstractSetobj = new TreeSet(); 
obj.add("Red"); 
obj.add("Green"); 
obj.add("Blue"); 
obj.add("Black"); 
obj.add("Orange"); 
System.out.println("AbstractSet: "+ obj); 
            } 
        catch (Exception e) 
	{ 
System.out.println(e); 
        } 
    } 
}

S.no.	Method	Description
1	add(E e)	It is used to add an element to the end of the Set.
2	clear()	It is used to remove all the elements from the Set.
3	equals(Object o)	It is used to compare an element from another element in the Set.
4	hashCode()	It is used to get hash code from the Set.
5	Iterator()	It returns all the elements from the Set. Using Iterator.
6	listIterator()	It is used to get the Iterated Set in a proper sequence.
7	remove(int index)	It is used to remove the specified element from the Set.

Example:


import java.util.*; 

public class AbstractSetDemo2 { 
    public static void main(String args[]) 
    { 
AbstractSet<String> set = new TreeSet<String>(); 
set.add("Dog"); 
set.add("Cat"); 
set.add("Bird"); 
set.add("Tiger"); 
set.add("Rabit"); 

	System.out.println("******************************
*****");
System.out.println("Elements in the set 1:" + set);
	AbstractSet<String> set1 = new TreeSet<String>();
	set1.add("Dog"); 
        set1.add("Cat"); 
        set1.add("Bird"); 
        set1.add("Tiger"); 
        set1.add("Rabit"); 
	System.out.println("*******************************
****************************");
System.out.println("Elements in the Set 2 :" + set1);
	System.out.println("*******************************
****************************");
	boolean a = set.equals(set1); 
	System.out.println("Are both set equal : "+ a); 
	System.out.println("*******************************
****************************");	
	int c= set.hashCode();
System.out.println("HashCode : " + c); 
	System.out.println("*******************************
****************************");
	Iterator e = set.iterator(); 
            while (e.hasNext()) 
		{ 
System.out.println("Element : "+ e.next()); 
		}
	System.out.println("*******************************
****************************");
	 } 
}