package HashSet_package; import java.util.LinkedHashSet; public class LinkedHashSet_demo { public static void main(String[] args) { //1、创建三个学生对象 Student s1 = new Student("zhangsan", 23); Student s2 = new Student("lisi", 24); Student s3 = new Student("wangwu", 25); Student s4 = new Student("zhangsan", 23); //2、创建集合用来添加学生 LinkedHashSet lhs = new LinkedHashSet<>(); //3、添加元素 System.out.println(lhs.add(s1)); System.out.println(lhs.add(s2)); System.out.println(lhs.add(s3)); System.out.println(lhs.add(s4)); //4、打印集合,反映添加的先后顺序 System.out.println(lhs); } }