编辑器
import java.util.TreeSet; public class Main { public static void main(String[] args) { TreeSet<String> cars = new TreeSet<>(); cars.add("Volvo"); cars.add("BMW"); cars.add("Ford"); cars.add("BMW"); // Duplicate cars.add("Mazda"); System.out.println("Size: " + cars.size()); } }
Size: 4
编辑器