Map containsValue() method in Java with Examples
Last Updated :
31 Dec, 2018
Improve
The java.util.Map.containsValue() method is used to check whether a particular value is being mapped by a single or more than one key in the Map. It takes the value as a parameter and returns True if that value is mapped by any of the key in the map.
Syntax:
Java
Java
boolean containsValue(Object Value)Parameters: The method takes just one parameter Value of Object type and refers to the value whose mapping is supposed to be checked by any key inside the map. Return Value: The method returns boolean true if the mapping of the value is detected else false. Below programs illustrate the java.util.Map.containsValue() method: Program 1: Mapping String Values to Integer Keys.
// Java code to illustrate the containsValue() method
import java.util.*;
public class Map_Demo {
public static void main(String[] args)
{
// Creating an empty Map
Map<Integer, String> map = new HashMap<Integer, String>();
// Mapping string values to int keys
map.put(10, "Geeks");
map.put(15, "4");
map.put(20, "Geeks");
map.put(25, "Welcomes");
map.put(30, "You");
// Displaying the Map
System.out.println("Initial Mappings are: " + map);
// Checking for the Value 'Geeks'
System.out.println("Is the value 'Geeks' present? " + map.containsValue("Geeks"));
// Checking for the Value 'World'
System.out.println("Is the value 'World' present? " + map.containsValue("World"));
}
}
Output:
Program 2: Mapping Integer Values to String Keys.
Initial Mappings are: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4}
Is the value 'Geeks' present? true
Is the value 'World' present? false
// Java code to illustrate the containsValue() method
import java.util.*;
public class Map_Demo {
public static void main(String[] args)
{
// Creating an empty Map
Map<String, Integer> map = new HashMap<String, Integer>();
// Mapping int values to string keys
map.put("Geeks", 10);
map.put("4", 15);
map.put("Geeks", 20);
map.put("Welcomes", 25);
map.put("You", 30);
// Displaying the Map
System.out.println("Initial Mappings are: " + map);
// Checking for the Value '10'
System.out.println("Is the value '10' present? " + map.containsValue(10));
// Checking for the Value '30'
System.out.println("Is the value '30' present? " + map.containsValue(30));
// Checking for the Value '40'
System.out.println("Is the value '40' present? " + map.containsValue(40));
}
}
Output:
Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Map.html#containsValue(java.lang.Object)
Initial Mappings are: {4=15, Geeks=20, You=30, Welcomes=25}
Is the value '10' present? false
Is the value '30' present? true
Is the value '40' present? false
