HashMap.keySet() has the following syntax.
public Set <K> keySet()
In the following code shows how to use HashMap.keySet() method.
/*from ww w .jav a 2 s . c o m*/ import java.util.HashMap; import java.util.Set; public class Main { public static void main(String args[]) { HashMap<Integer, String> newmap = new HashMap<Integer, String>(); // populate hash map newmap.put(1, "tutorials"); newmap.put(2, "from"); newmap.put(3, "java2s.com"); // get keyset value from map Set keyset=newmap.keySet(); // check key set values System.out.println("Key set values are: " + keyset); } }
The code above generates the following result.