Java TreeMap containsValue() Method

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Description

The Java TreeMap containsValue(Object value) method is used to return true if this map, maps one or more keys to the specified value.

Declaration

Following is the declaration for java.util.TreeMap.containsValue() method.

public boolean containsValue(Object value)

Parameters

value − This is the value whose presence in this map is to be tested.

Return Value

The method call returns true if a mapping to this value exists otherwise false.

Exception

NA

Checking If Value Exists in a TreeMap of Integer, Integer Pair Example

The following example shows the usage of Java TreeMap containsValue() method to check if a value is present in a map or not. We've created a TreeMap object of Integer,Integer pairs. Then few entries are added to map and using containsValue() we're checking if value is present and then printing the same.

package com.tutorialspoint;

import java.util.TreeMap;

public class TreeMapDemo {
   public static void main(String[] args) {
      
      // creating tree map 
      TreeMap<Integer, Integer> treemap = new TreeMap<>();

      // populating tree map
      treemap.put(2, 2);
      treemap.put(1, 1);
      treemap.put(3, 3);
      treemap.put(6, 6);
      treemap.put(5, 5);

      System.out.println("Checking value");
      System.out.println("3 exists: "+ treemap.containsValue(3));
   }    
}

Output

Let us compile and run the above program, this will produce the following result.

Checking value
3 exists: true

Checking If Value Exists in a TreeMap of Integer, String Pair Example

The following example shows the usage of Java TreeMap containsValue() method to check if a value is present in a map or not. We've created a TreeMap object of Integer,String pairs. Then few entries are added to map and using containsValue() we're checking if value is present and then printing the same.

package com.tutorialspoint;

import java.util.TreeMap;

public class TreeMapDemo {
   public static void main(String[] args) {
      
      // creating tree map 
      TreeMap<Integer, String> treemap = new TreeMap<>();

      // populating tree map
      treemap.put(2, "two");
      treemap.put(1, "one");
      treemap.put(3, "three");
      treemap.put(6, "six");
      treemap.put(5, "five");

      System.out.println("Checking value");
      System.out.println("'three' exists: "+ treemap.containsValue("three"));
   }    
}

Output

Let us compile and run the above program, this will produce the following result.

Checking value
'three' exists: true

Checking If Value Exists in a TreeMap of Integer, Object Pair Example

The following example shows the usage of Java TreeMap containsValue() method to check if a value is present in a map or not. We've created a TreeMap object of Integer,Student pairs. Then few entries are added to map and using containsValue() we're checking if value is present and then printing the same.

package com.tutorialspoint;

import java.util.TreeMap;

public class TreeMapDemo {
   public static void main(String[] args) {
      
      // creating tree map 
      TreeMap<Integer, Student> treemap = new TreeMap<>();

      // populating tree map
      treemap.put(2, new Student(2, "Robert"));
      treemap.put(1, new Student(1, "Julie"));  
      treemap.put(3, new Student(3, "Adam"));
      treemap.put(6, new Student(6, "Julia"));
      treemap.put(5, new Student(5, "Tom"));

      System.out.println("Checking value");
      System.out.println("Adam exists: "+ treemap.containsValue(new Student(3, "Adam")));
   }    
}
class Student {
   int rollNo;
   String name;

   Student(int rollNo, String name){
      this.rollNo = rollNo;
      this.name = name;
   }

   @Override
   public String toString() {
      return "[ " + this.rollNo + ", " + this.name + " ]";
   }
   @Override
   public boolean equals(Object obj) {
      if(obj == null) return false;
      Student s = (Student)obj;
      return this.rollNo == s.rollNo && this.name.equalsIgnoreCase(s.name);
   }
}

Output

Let us compile and run the above program, this will produce the following result.

Checking value
Adam exists: true