Java.util.EnumMap.containsKey() Method


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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

java_util_enummap.htm

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