java.util.HashMap.keySet() Method


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Description

The keySet() method is used to get a Set view of the keys contained in this map.

Declaration

Following is the declaration for java.util.HashMap.keySet() method.

public Set<K> keySet()

Parameters

  • NA

Return Value

The method call returns a set view of the keys contained in this map.

Exception

  • NA

Example

The following example shows the usage of java.util.HashMap.keySet()

package com.tutorialspoint;

import java.util.*;

public class HashMapDemo {
   public static void main(String args[]) {
   // create hash map
   HashMap newmap = new HashMap();
      
   // populate hash map
   newmap.put(1, "tutorials");
   newmap.put(2, "point");
   newmap.put(3, "is best");
      
   // get keyset value from map
   Set keyset=newmap.keySet();
      
   // check key set values
   System.out.println("Key set values are: " + keyset);
   }    
}

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

Key set values are: [1, 2, 3]

java_util_hashmap.htm

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