EnumMap containsKey() Method in Java

Last Updated : 24 Jul, 2020

The Java.util.EnumMap.containsKey(key) method is used to check whether a specified key mentioned in the parameter is present in this map or not. Syntax:

boolean containsKey(Object key)

Parameter: The method accepts one parameter key which refer to the key to be verified. Return Value: The method returns true if the key is present in the EnumMap otherwise it returns false. Below programs illustrate the containsKey() method: Program 1:

Java

// Java program to demonstrate containsKey() method
import java.util.*;

// An enum of gfg visitors is created
public enum gfg_visitors {
    India,
    United_States,
    China,
    Japan,
    Canada
};

class Enum_map {
    public static void main(String[] args)
    {

        EnumMap<gfg_visitors, String> mp = new 
        EnumMap<gfg_visitors, String>(gfg_visitors.class);

        // values are associated in mp
        mp.put(gfg_visitors.India, "61.4%");
        mp.put(gfg_visitors.United_States, "18.4%");
        mp.put(gfg_visitors.China, "2.5%");
        mp.put(gfg_visitors.Japan, "1.1%");
        mp.put(gfg_visitors.Canada, "1.1%");

        // Check if map contains gfg visitor from United_States
        boolean ans = mp.containsKey(gfg_visitors.United_States);

        // Prints the result
        System.out.println("gfg_visitors from United States: " + ans);
    }
}

Output:

gfg_visitors from United States: true

Program 2:

Java

// Java program to demonstrate containsKey() method
import java.util.*;

// An enum of gfg visitors is created
public enum gfg_visitors {
    India,
    United_States,
    China,
    Japan,
    Canada,
    Russia
};

class Enum_map {
    public static void main(String[] args)
    {

        EnumMap<gfg_visitors, String> mp = new 
        EnumMap<gfg_visitors, String>(gfg_visitors.class);

        // values are associated in mp
        mp.put(gfg_visitors.India, "61.4%");
        mp.put(gfg_visitors.United_States, "18.4%");
        mp.put(gfg_visitors.China, "2.5%");
        mp.put(gfg_visitors.Japan, "1.1%");
        mp.put(gfg_visitors.Canada, "1.1%");

        // check if map contains gfg visitor from Russia
        boolean ans = mp.containsKey(gfg_visitors.Russia);

        // prints the result
        System.out.println("gfg_visitors from Russia: " + ans);
    }
}