Java Basic example program to check particular value exists in hashmap

1.Basic Java example program to check particular value exists in hashmap

1. package com.javacheckvaluehashmap;
2.  
3. import java.util.Hashmap;
4. import java.util.Iterator;
5. import java.util.Map;
6. import java.util.Map.Entry;
7.  
8. public class HashmapExample{
9.  
10. public static void main(String[] args) {
11.   
12. //create an Hashmap object
13. HashMap<String, String> hashmap = new HashMap();
14.        
15. //Add key values pairs to hashmap
16.         
17. hashmap.put("1","One");
18. hashmap.put("2","Two");
19. hashmap.put("3","Three");
20. hashmap.put("4","Four");
21. hashmap.put("5","Five");
22. hashmap.put("6","Six");       
23.         
24.  
25.  /*
26.  To check whether a particular value exists in HashMap use
27.  boolean containsValue(Object value) method of HashMap class.
28. containsValue(Object value) returns true if the HashMap contains mapping for specified
29. value otherwise false.*/
30.        
31. boolean isExists = hashmap.containsValue("Six");
32. System.out.println("The value Six exists in HashMap ? : " + isExists);
33.     
34.  
35. if(!hashmap.isEmpty()){
36.  
37. Iterator it=hashmap.entrySet().iterator();
38.              
39. while(it.hasNext()){
40. 
    
41. Map.Entry obj=(Entry) it.next();
42. System.out.print(obj.getKey()+" ");
43. System.out.println(obj.getValue());
44.              
45. }           
46. }   
47.  
48. }
49.  
50. }
     

Output:

1. The value Six exists in HashMap ? : true
2. 1 One
3. 2 Two
4. 3 Three
5. 4 Four
6. 5 Five
7. 6 Six