Java.util.EnumMap.containsKey() Method

Description

The java.util.EnumMap.containsKey(Object key) method determines if this map contains a mapping for the specified key.

Declaration

Following is the declaration for java.util.EnumMap.containsKey() method

public boolean containsKey(Object key)

Parameters

• key-- the key whose presence in this map is to be tested

Return Value

This method returns true if this map contains a mapping for the specified key.

Exception

• NA

Example

The following example shows the usage of java.util.EnumMap.containsKey() method.

package com.tutorialspoint;

import java.util.EnumMap;

public class EnumMapDemo {

   // create an enum
   public enum Numbers {

      ONE, TWO, THREE, FOUR, FIVE
   };

   public static void main(String[] args) {
      EnumMap<Numbers, String> map =
              new EnumMap<Numbers, String>(Numbers.class);

      // associate values in map
      map.put(Numbers.ONE, "1");
      map.put(Numbers.TWO, "2");
      map.put(Numbers.THREE, "3");
      map.put(Numbers.FOUR, "4");

      // print the whole map
      System.out.println(map);

      // check if map contains a mapping at specified key
      boolean contains = map.containsKey(Numbers.ONE);

      // print the result
      System.out.println("Numbers.ONE has a mapping:" + contains);

      // check if map contains a mapping at another specified key
      contains = map.containsKey(Numbers.FIVE);

      // print the result
      System.out.println("Numbers.FIVE has a mapping:" + contains);

   }
}

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

{ONE=1, TWO=2, THREE=3, FOUR=4}
Numbers.ONE has a mapping:true
Numbers.FIVE has a mapping:false