Java Collections example program Get Set view of Keys from Hashtable example

1.Basic java collection framework example program to get set view from hashtable

• Set keySet()   This method used to get set view of the keys of hashtable
•  Important note is that if any key is removed from set the original hashtable key also removed

1. package com.setviewHashtable;
2.  
3. import java.util.Hashtable;
4. 
   
5. import java.util.Enumeration;
6. import java.util.Iterator;
7. import java.util.Set;
8.  
9. public class HashtableExample{
10.  
11. public static void main(String[] args) {
12.   
13.  //create Hashtable object
14.        Hashtable<String,String> hashtable = new Hashtable<String,String>();
15.        
16. //add key value pairs to Hashtable
17. hashtable.put("1","Java Interview Questions");
18. hashtable.put("2","Java Interview Programs");
19. hashtable.put("3","Concept and example program");
20. hashtable.put("4","Concept and interview Questions");
21. hashtable.put("5","Java Quiz");
22. hashtable.put("6","Real time examples");
23.  
24.  
25.  Set st = hashtable.keySet();       
26.  System.out.println("Set created from Hashtable Keys contains :");
27. //iterate through the Set of keys
28.  
29.  Iterator itr = st.iterator();
30.  while(itr.hasNext())
31.  System.out.println(itr.next());
32.            
33.  st.remove("1");
34.            
35. System.out.println("Elements in hash table");
36. Enumeration e=hashtable.keys();
37.         
38.  
39.  while (e.hasMoreElements()) {
40.         System.out.println(e.nextElement());
41. }    
42. 
    
43. }
44.  
45. }
     

Output:

1. Set created from Hashtable Keys contains :
2. 6
3. 5
4. 4
5. 3
6. 2
7. 1
8. Elements in hash table
9. 6
10. 5
11. 4
12. 3
13. 2