Java LinkedHashMap containsValue() Method

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Description

The Java LinkedHashMap containsValue(Object value) method returns true if this map maps one or more keys to the specified value.

Declaration

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

public boolean containsValue(Object value)

Parameters

value − value whose presence in this map is to be tested

Return Value

This method returns true if this map maps one or more keys to the specified value

Exception

NA

Checking a Value to be Present in a LinkedHashMap of Integer, Integer Pair Example

The following example shows the usage of Java LinkedHashMap containsValue() method to check if a value is present in a Map or not. We've created a Map object of Integer,Integer pair. Then few entries are added, map is printed and using containsValue() we're checking about two values in the map.

package com.tutorialspoint;

import java.util.LinkedHashMap;

public class LinkedHashMapDemo {
   public static void main(String args[]) {
      
      // create hash map
      LinkedHashMap<Integer,Integer> newmap = new LinkedHashMap<>();

      // populate hash map
      newmap.put(1, 1);
      newmap.put(2, 2);
      newmap.put(3, 3); 

      System.out.println("Initial map elements: " + newmap);
      System.out.println("Map contains 2 as value: " + newmap.containsValue(2));
      System.out.println("Map contains 4 as value: " + newmap.containsValue(4));
   }    
}

Output

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

Initial map elements: {1=1, 2=2, 3=3}
Map contains 2 as value: true
Map contains 4 as value: false

Checking a Value to be Present in a LinkedHashMap of Integer, String Pair Example

The following example shows the usage of Java LinkedHashMap containsValue() method to check if a value is present in a Map or not. We've created a Map object of Integer,String pair. Then few entries are added, map is printed and using containsValue() we're checking about two values in the map.

package com.tutorialspoint;

import java.util.LinkedHashMap;

public class LinkedHashMapDemo {
   public static void main(String args[]) {
      
      // create hash map
      LinkedHashMap<Integer,String> newmap = new LinkedHashMap<>();

      // populate hash map
      newmap.put(1, "tutorials");
      newmap.put(2, "point");
      newmap.put(3, "is best"); 

      System.out.println("Initial map elements: " + newmap);
      System.out.println("Map contains tutorials as value: " + newmap.containsValue("tutorials"));
      System.out.println("Map contains java as value: " + newmap.containsValue("java"));
   }    
}

Output

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

Initial map elements: {1=tutorials, 2=point, 3=is best}
Map contains tutorials as value: true
Map contains java as value: false

Checking a Value to be Present in a LinkedHashMap of Integer, Object Pair Example

The following example shows the usage of Java LinkedHashMap containsValue() method to check if a value is present in a Map or not. We've created a Map object of Integer,Student pair. Then few entries are added, map is printed and using containsValue() we're checking about two values in the map.

package com.tutorialspoint;

import java.util.LinkedHashMap;

public class LinkedHashMapDemo {
   public static void main(String args[]) {
      
      // create hash map
      LinkedHashMap<Integer,Student> newmap = new LinkedHashMap<>();

      // populate hash map
      newmap.put(1, new Student(1, "Julie"));
      newmap.put(2, new Student(2, "Robert"));
      newmap.put(3, new Student(3, "Adam"));

      System.out.println("Initial map elements: " + newmap);
      System.out.println("Map contains Robert as value: " + newmap.containsValue(new Student(2, "Robert")));
      System.out.println("Map contains Jene as value: " + newmap.containsValue(new Student(4, "Jene")));
   }    
}
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.

Initial map elements: {1=[ 1, Julie ], 2=[ 2, Robert ], 3=[ 3, Adam ]}
Map contains Robert as value: true
Map contains Jene as value: false