Java.util.EnumMap.putAll() Method


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Description

The java.util.EnumMap.putAll(Map<? extends K,? extends V> m) method copies all of the mappings from the specified map to this map. Older values are replaced.

Declaration

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

public void putAll(Map<? extends K,? extends V> m)

Parameters

m − the mappings to be stored in this map

Return Value

This method does not return any value.

Exception

NullPointerException − the specified map is null, or if one or more keys in the specified map are null

Example

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

Live Demo
package com.tutorialspoint;

import java.util.*;

public class EnumMapDemo {

   // create an enum
   public enum Numbers {
      ONE, TWO, THREE, FOUR, FIVE
   };

   public static void main(String[] args) {
      
      EnumMap<Numbers, String> map1 =
         new EnumMap<Numbers, String>(Numbers.class);
      EnumMap<Numbers, String> map2 =
         new EnumMap<Numbers, String>(Numbers.class);

      // associate values in map1
      map1.put(Numbers.ONE, "1");
      map1.put(Numbers.TWO, "2");
      map1.put(Numbers.THREE, "3");
      map1.put(Numbers.FOUR, "4");

      // print the maps
      System.out.println("Map1: " + map1);
      System.out.println("Map2: " + map2);

      // put all mapping from map1 to map 2
      map2.putAll(map1);

      // print the maps
      System.out.println("Map1: " + map1);
      System.out.println("Map2: " + map2);
   }
}

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

Map1: {ONE=1, TWO=2, THREE=3, FOUR=4}
Map2: {}
Map1: {ONE=1, TWO=2, THREE=3, FOUR=4}
Map2: {ONE=1, TWO=2, THREE=3, FOUR=4}

java_util_enummap.htm

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