public class Person { private String name; private int age; public Person() { } public Person(String name, int age) { this.name = name; this.age = age; } public void gomethod() { System.out.println("欢迎来到北京!北京欢迎你!"); } }
import java.util.ArrayList; import java.util.Collection; import java.util.Date; /** * PrivateRyan * 2021.11.7 * 集合强化练习 */ public class Colection84 { public static void main(String[] args) { //创建集合,并添加元素 Collection coll=new ArrayList(); coll.add(new Date()); System.out.println(coll); coll.add("MM"); coll.add(896);//包装类 coll.add(new String("魅力四射")); System.out.println(coll); Collection colle=new ArrayList(); colle.add("希望的田野"); coll.addAll(colle); System.out.println(coll); System.out.println(colle.isEmpty()); colle.clear(); System.out.println(colle); System.out.println("***************************************"); System.out.println(coll.size()); System.out.println(coll.getClass()); System.out.println(coll.contains(896)); System.out.println("***************************************"); Person p=new Person("小红",20); coll.add(p); System.out.println(coll); System.out.println(coll.contains(p)); } }