Check if a value exists in a TreeMap in Java

To check if a value associated with a key exists in TreeMap in Java, you need to call the containsKey()  of the TreeMap.

public boolean containsValue(Object val): This method returns a true boolean if the TreeMap contains at least one instance of the value you are looking for val, otherwise false. This method is possible since Java version 1.2.

import java.util.*; 

public class Recherche_valeur_treemap {
 public static void main(String[] args) {
 // creating TreeMap
 TreeMap< String, String> treemap = new TreeMap< String, String> (); 
 
 // insert into treemap
 treemap.put("1", "a"); 
 treemap.put("2", "b"); 
 treemap.put("3", "c"); 
 treemap.put("4", "d"); 
 treemap.put("5", "e"); 
 
 //display key elements and value
 Set set=treemap.keySet(); 
 Iterator iterator = set.iterator(); 
 while(iterator.hasNext()){
 String key = ((String) iterator.next()); 
 String val = ((String) treemap.get(key)); 
 System.out.println(key+"-> "+val); 
 }
 
 boolean exists = treemap.containsValue("a"); 
 System.out.println("the value a exists in the list: "+exists); 
 
 exists = treemap.containsValue("f"); 
 System.out.println("the f value exists in the list: "+exists); 
 
 } 
}

Output:

1-> a
2-> b
3-> c
4-> d
5-> e
the a value exists in the list: true
the f value exists in the list: false

References:
JavaDoc: TreeMap containsValue() method