Набор Java содержит

// Java code to illustrate Set.contains() method
import java.io.*;
import java.util.*;
  
public class HashSetDemo {
    public static void main(String args[])
    {
        // Creating an empty Set
        Set<String> set = new HashSet<String>();
  
        // Using add() method to add elements into the Set
        set.add("Welcome");
        set.add("To");
        set.add("Geeks");
        set.add("4");
        set.add("Geeks");
  
        // Displaying the Set
        System.out.println("Set: " + set);
  
        // Check for "Geeks" in the set
        System.out.println("Does the Set contains 'Geeks'? "
                           + set.contains("Geeks"));
  
        // Check for "4" in the set
        System.out.println("Does the Set contains '4'? "
                           + set.contains("4"));
  
        // Check if the Set contains "No"
        System.out.println("Does the Set contains 'No'? "
                           + set.contains("No"));
    }
}
Courageous Cottonmouth