JAVA第19次上机作业

把多个企鹅的信息添加到集合中

查看企鹅的数量及所有企鹅的信息

删除集合中部分企鹅的元素

判断集合中是否包含指定企鹅

import java.util.ArrayList;

import java.util.List;

public class TestList {

 public static void main(String[] args) {

  List<QQ> list = new ArrayList<QQ>();

  QQ q1 = new QQ(1, "qq1", "info1");

  QQ q2 = new QQ(2, "qq2", "info2");

  QQ q3 = new QQ(3, "qq3", "info3");

  QQ q4 = new QQ(4, "qq4", "info4");

  list.add(q1);

  list.add(1, q2);

  list.add(q3);

  list.add(q4);

  for (QQ qq : list) {

   System.out.println(qq);

  }

  QQ temp = null;

  for (int i = 0; i < list.size(); i++) {

   temp = list.get(i);

   System.out.println(temp);

  }

  for (int i = list.size() - 1; i >= 0; i--) {

   temp = list.get(i);

   System.out.println(temp);

  }

  QQ find = new QQ(3);

  int id = list.indexOf(find);

  if (id >= 0) {

   find = list.get(id);

   System.out.println("id=" + id + find);

  }

  QQ ex = new QQ(1);

  boolean exist = list.contains(ex);

  if (exist) {

   System.out.println("集合中存在帐号=" + ex.getId() + "的QQ");

  } else {

   System.out.println("集合中不存在帐号=" + ex.getId() + "的QQ");

  }

  QQ del1 = new QQ(1);

  QQ del5 = new QQ(5);

  boolean result1 = list.remove(del1);

  boolean result5 = list.remove(del5);

  if (result1) {

   System.out.println("删除帐号id=" + del1.getId() + "成功");

  } else {

   System.out.println("删除帐号id=" + del1.getId() + "失败");

  }

  System.out.println(list.size());

  if (result5) {

   System.out.println("删除帐号id=" + del5.getId() + "成功");

  } else {

   System.out.println("删除帐号id=" + del5.getId() + "失败");

  }

  System.out.println(list.size());

 }

}

class QQ {

 private long id;

 private String name;

 private String info;

 public long getId() {

  return id;

 }

 public QQ() {

 }

 public QQ(long id) {

  this.id = id;

 }

 public QQ(long id, String name, String info) {

  super();

  this.id = id;

  this.name = name;

  this.info = info;

 }

 public void setId(long id) {

  this.id = id;

 }

 public String getName() {

  return name;

 }

 public void setName(String name) {

  this.name = name;

 }

 public String getInfo() {

  return info;

 }

 public void setInfo(String info) {

  this.info = info;

 }

 public boolean equals(Object obj) {

  if (obj == null) {

   return false;

  }

  if (this == obj) {

   return true;

  }

  if (obj instanceof QQ) {

   return ((QQ) obj).getId() == getId();

  }

  return false;

 }

 public String toString() {

  return "[id=" + getId() + ",name=" + getName() + ",info=" + getInfo()

    + "]";

 }

}