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);  } }