HashSet contains(Object o) method in java
import java.util.HashSet;
public class HashSetContainsObjectMethodExample
{
public static void main(String[] args)
{
HashSet<String> hs = new HashSet<String>();
hs.add("hello");
hs.add("world");
hs.add("java");
// check if element exists
boolean bool = hs.contains("world");
System.out.println("Is element 'world' exists: " + bool);
}
}