201771010137 赵栋《面向对象程序设计(java)》第十一周学习总结
一:理论部分。
1.数据结构:分为a.线性数据结构,如线性表、栈、队列、串、数组和文件。
b.非线性数据结构,如树和图。
1)所有数据元素在同一个线性表中必须是相同的数据类型。
线性表按其存储结构可分为顺序表和链表。
2)栈:也是一种特殊的线性表,是一种后进先出(LIFO)的结构。
栈是限定仅在表尾进行插入和删除运算的线性表,表尾称为栈顶,表头称为栈底。
3)队列:限定所有的插入只能在表的一端进行,而所有的删除都在表的另一端进行的线性表。是一种先进先出(FIFO)的结构。
表中允许插入的一端称为队尾,允许删除的一端称为队头。
2.集合:(容器)是一种包含多个元素并提供对所包含元素操作方法的类,其包含的元素可以由同一类型的对象组成,也可以由不同类型的对象组成。
1)集合框架:JAVA集合类库的统一架构。
2)集合类的作用(包含在java.util包中):提供一些基本数据结构的支持,如Vector、Hashtable、Stack等。
3)集合类的特点:a.只容纳对象;
b.集合类容纳的对象都是Object类的实例(一旦把一个对象置入集合类中,它的类信息将丢失)
4)Vector类:类似长度可变的数组。它只能存放对象,其元素通过下标进行访问。
5)Stack类(Vector的子类):它描述堆栈数据结构。(所有对象都有一个散列码,可以通过Object类的hashCode方法获得。)
3.集合框架中的基本接口:a.Collection(构造类集框架的基础):集合层次中的根接口,JDK未提供这个接口的直接实现类。
b.Set:不能包含重复的元素,即元素必须唯一。对象可能不是按存放的次序存放。(实 现 Set 接口的类有HashSet,TreeSet)
c.List:有序的集合,可以包含重复的元素。提供了按索引访问的方式。实现它的类有ArrayList和LinkedLis(如ArrayList:能够自动增长容量的数组)
d.Map:Map接口映射唯一关键字到值。包含了key-value对。Map不能包含重复的key。SortedMap是一个按照升序排列key的Map。
二:实验部分。
1、实验目的与要求
(1) 掌握Vetor、Stack、Hashtable三个类的用途及常用API;
(2) 了解java集合框架体系组成;
(3) 掌握ArrayList、LinkList两个类的用途及常用API。
(4) 了解HashSet类、TreeSet类的用途及常用API。
(5)了解HashMap、TreeMap两个类的用途及常用API;
(6) 结对编程(Pair programming)练习,体验程序开发中的两人合作。
2、实验内容和步骤
实验1: 导入第9章示例程序,测试程序并进行代码注释。
测试程序1:
l 使用JDK命令运行编辑、运行以下三个示例程序,结合运行结果理解程序;
l 掌握Vetor、Stack、Hashtable三个类的用途及常用API。
示例程序1:
import java.util.Vector; class Cat { private int catNumber; Cat(int i) { catNumber = i; } void print() { System.out.println("Cat #" + catNumber); } } class Dog { private int dogNumber; Dog(int i) { dogNumber = i; } void print() { System.out.println("Dog #" + dogNumber); } } public class CatsAndDogs { public static void main(String[] args) { Vector cats = new Vector(); for (int i = 0; i < 7; i++) cats.addElement(new Cat(i)); cats.addElement(new Dog(7)); for (int i = 0; i < cats.size(); i++) ((Cat) cats.elementAt(i)).print();//进行强制类型转化 } }
程序运行结果如下:
由程序运行结果可知,程序在强制转换类型时出现异常,更改后程序如下:
import java.util.Vector; class Cat { private int catNumber; Cat(int i) { catNumber = i; } void print() { System.out.println("Cat #" + catNumber); } } class Dog { private int dogNumber; Dog(int i) { dogNumber = i; } void print() { System.out.println("Dog #" + dogNumber); } } public class CatsAndDogs { public static void main(String[] args) { Vector cats = new Vector(); for (int i = 0; i < 7; i++) cats.addElement(new Cat(i)); cats.addElement(new Dog(7)); for (int i = 0; i < cats.size(); i++) if (cats.elementAt(i) instanceof Cat) //判断是否能进行强制类型转换 { ((Cat) cats.elementAt(i)).print();//能进行强制类型转换,输出为Cat型 } else { ((Dog) cats.elementAt(i)).print();//不能进行强制类型转化,输出为Dog型 } } }
程序运行结果如下:
示例程序2:
import java.util.*; public class 333{
static String[] months = { "1", "2", "3", "4" }; public static void main(String[] args) { Stack stk = new Stack(); for (int i = 0; i < months.length; i++) stk.push(months[i]);//进栈 System.out.println(stk); System.out.println("element 2=" + stk.elementAt(2)); while (!stk.empty()) System.out.println(stk.pop());//输出出栈元素 } }
程序运行结果如下:
示例程序3:
import java.util.*; class Counter {
int i = 1; public String toString() { return Integer.toString(i); } } public class Statistics { public static void main(String[] args) { Hashtable ht = new Hashtable(); for (int i = 0; i < 10000; i++) { Integer r = new Integer((int) (Math.random() * 20)); if (ht.containsKey(r)) ((Counter) ht.get(r)).i++; else ht.put(r, new Counter()); } System.out.println(ht); } }
程序运行结果如下:
测试程序2:
使用JDK命令编辑运行ArrayListDemo和LinkedListDemo两个程序,结合程序运行结果理解程序;
ArrayListDemo:
import java.util.*; public class ArrayListDemo { public static void main(String[] argv) { ArrayList al = new ArrayList(); al.add(new Integer(11)); al.add(new Integer(12)); al.add(new Integer(13)); al.add(new String("hello")); // First print them out using a for loop. System.out.println("Retrieving by index:"); for (int i = 0; i < al.size(); i++) { System.out.println("Element " + i + " = " + al.get(i)); } } }
程序运行结果如下:
LinkedListDemo:
程序运行结果如下:
l 在Elipse环境下编辑运行调试教材360页程序9-1,结合程序运行结果理解程序;
l 掌握ArrayList、LinkList两个类的用途及常用API。
程序如下:
import java.util.*; /** * This program demonstrates operations on linked lists. * @version 1.11 2012-01-26 * @author Cay Horstmann */ public class LinkedListTest { public static void main(String[] args) { List<String> a = new LinkedList<>(); a.add("Amy"); a.add("Carl"); a.add("Erica"); List<String> b = new LinkedList<>(); b.add("Bob"); b.add("Doug"); b.add("Frances"); b.add("Gloria"); ListIterator<String> aIter = a.listIterator(); Iterator<String> bIter = b.iterator(); while (bIter.hasNext()) { if (aIter.hasNext()) aIter.next(); aIter.add(bIter.next()); } System.out.println(a); bIter = b.iterator(); while (bIter.hasNext()) { bIter.next();
if (bIter.hasNext()) { bIter.next(); bIter.remove(); } } System.out.println(b); a.removeAll(b); System.out.println(a); } }
程序运行结果如下:
测试程序3:
l 运行SetDemo程序,结合运行结果理解程序;
程序如下:
import java.util.*; public class SetDemo { public static void main(String[] argv) { HashSet h = new HashSet(); //也可以 Set h=new HashSet() h.add("One"); h.add("Two"); h.add("One"); h.add("Three"); Iterator it = h.iterator(); while (it.hasNext()) { System.out.println(it.next()); } } }
程序运行结果如下:
l 在Elipse环境下调试教材367页-368程序9-3、9-4,结合程序运行结果理解程序;了解TreeSet类的用途及常用API。
9—3:
import java.util.*; /** * An item with a description and a part number. */ public class Item implements Comparable<Item> { private String description; private int partNumber; /** * Constructs an item. * * @param aDescription * the item's description * @param aPartNumber * the item's part number */ public Item(String aDescription, int aPartNumber) { description = aDescription; partNumber = aPartNumber; } /** * Gets the description of this item. * * @return the description */ public String getDescription() { return description; } public String toString() { return "[description=" + description + ", partNumber=" + partNumber + "]"; } public boolean equals(Object otherObject) { if (this == otherObject) return true; if (otherObject == null) return false; if (getClass() != otherObject.getClass()) return false; Item other = (Item) otherObject; return Objects.equals(description, other.description) && partNumber == other.partNumber; } public int hashCode() { return Objects.hash(description, partNumber); } public int compareTo(Item other) { int diff = Integer.compare(partNumber, other.partNumber); return diff != 0 ? diff : description.compareTo(other.description); } }
程序运行结果如下:
9—4:
import java.util.*; /** * This program sorts a set of item by comparing their descriptions. * @version 1.12 2015-06-21 * @author Cay Horstmann */ public class TreeSetTest { public static void main(String[] args) { SortedSet<Item> parts = new TreeSet<>(); parts.add(new Item("Toaster", 1234)); parts.add(new Item("Widget", 4562)); parts.add(new Item("Modem", 9912)); System.out.println(parts); NavigableSet<Item> sortByDescription = new TreeSet<>( Comparator.comparing(Item::getDescription)); sortByDescription.addAll(parts); System.out.println(sortByDescription); } }
程序运行结果如图:
测试程序4:
l 使用JDK命令运行HashMapDemo程序,结合程序运行结果理解程序;
程序如下:
import java.util.*; public class HashMapDemo { public static void main(String[] argv) { HashMap h = new HashMap(); // 哈希映射从公司名称到地址 h.put("Adobe", "Mountain View, CA"); h.put("IBM", "White Plains, NY"); h.put("Sun", "Mountain View, CA"); String queryString = "Adobe"; String resultString = (String)h.get(queryString); System.out.println("They are located in: " + resultString); } }
程序运行结果:
在Elipse环境下调试教材373页程序9-6,结合程序运行结果理解程序;
了解HashMap、TreeMap两个类的用途及常用API。
程序如下:
import java.util.*; /** * This program demonstrates the use of a map with key type String and value type Employee. * @version 1.12 2015-06-21 * @author Cay Horstmann */ public class MapTest { public static void main(String[] args) { Map<String, Employee> staff = new HashMap<>(); staff.put("144-25-5464", new Employee("Amy Lee")); staff.put("567-24-2546", new Employee("Harry Hacker")); staff.put("157-62-7935", new Employee("Gary Cooper")); staff.put("456-62-5527", new Employee("Francesca Cruz")); System.out.println(staff); staff.remove("567-24-2546"); staff.put("456-62-5527", new Employee("Francesca Miller")); System.out.println(staff.get("157-62-7935")); staff.forEach((k, v) -> System.out.println("key=" + k + ", value=" + v)); } }
程序运行结果如下:
实验2:结对编程练习:
l 关于结对编程:以下图片是一个结对编程场景:两位学习伙伴坐在一起,面对着同一台显示器,使用着同一键盘,同一个鼠标,他们一起思考问题,一起分析问题,一起编写程序。
l 关于结对编程的阐述可参见以下链接:
http://www.cnblogs.com/xinz/archive/2011/08/07/2130332.html
http://en.wikipedia.org/wiki/Pair_programming
l 对于结对编程中代码设计规范的要求参考:
http://www.cnblogs.com/xinz/archive/2011/11/20/2255971.html
以下实验,就让我们来体验一下结对编程的魅力。
l 确定本次实验结对编程合作伙伴:东文才
l 各自运行合作伙伴实验九编程练习1,结合使用体验对所运行程序提出完善建议;
1 import java.io.BufferedReader; 2 import java.io.File; 3 import java.io.FileInputStream; 4 import java.io.FileNotFoundException; 5 import java.io.IOException; 6 import java.io.InputStreamReader; 7 import java.util.ArrayList; 8 import java.util.Arrays; 9 import java.util.Collections; 10 import java.util.Scanner; 11 12 public class ee { 13 private static ArrayList<Student> studentlist; 14 public static void main(String[] args) { 15 16 studentlist = new ArrayList<>(); 17 Scanner scanner = new Scanner(System.in); 18 File file = new File("F:\java\身份证号.txt"); 19 try { 20 FileInputStream fis = new FileInputStream(file); 21 BufferedReader in = new BufferedReader(new InputStreamReader(fis)); 22 String temp = null; 23 while ((temp = in.readLine()) != null) { 24 25 Scanner linescanner = new Scanner(temp); 26 27 linescanner.useDelimiter(" "); 28 String name = linescanner.next(); 29 String number = linescanner.next(); 30 String sex = linescanner.next(); 31 String age = linescanner.next(); 32 String province =linescanner.nextLine(); 33 Student student = new Student(); 34 student.setName(name); 35 student.setnumber(number); 36 student.setsex(sex); 37 int a = Integer.parseInt(age); 38 student.setage(a); 39 student.setprovince(province); 40 studentlist.add(student); 41 42 } 43 } catch (FileNotFoundException e) { 44 System.out.println("找不到学生的信息文件"); 45 e.printStackTrace(); 46 } catch (IOException e) { 47 System.out.println("学生信息文件读取错误"); 48 e.printStackTrace(); 49 } 50 boolean isTrue = true; 51 while (isTrue) { 52 System.out.println("选择你的操作, "); 53 System.out.println("1.字典排序 "); 54 System.out.println("2.输出年龄最大和年龄最小的人 "); 55 System.out.println("3.寻找同乡 "); 56 System.out.println("4.寻找年龄相近的人 "); 57 System.out.println("5.退出 "); 58 String m = scanner.next(); 59 switch (m) { 60 case "1": 61 Collections.sort(studentlist); 62 System.out.println(studentlist.toString()); 63 break; 64 case "2": 65 int max=0,min=100; 66 int j,k1 = 0,k2=0; 67 for(int i=1;i<studentlist.size();i++) 68 { 69 j=studentlist.get(i).getage(); 70 if(j>max) 71 { 72 max=j; 73 k1=i; 74 } 75 if(j<min) 76 { 77 min=j; 78 k2=i; 79 } 80 81 } 82 System.out.println("年龄最大:"+studentlist.get(k1)); 83 System.out.println("年龄最小:"+studentlist.get(k2)); 84 break; 85 case "3": 86 System.out.println("地址?"); 87 String find = scanner.next(); 88 String place=find.substring(0,3); 89 for (int i = 0; i <studentlist.size(); i++) 90 { 91 if(studentlist.get(i).getprovince().substring(1,4).equals(place)) 92 System.out.println("同乡"+studentlist.get(i)); 93 } 94 break; 95 96 case "4": 97 System.out.println("年龄:"); 98 int yourage = scanner.nextInt(); 99 int near=agenear(yourage); 100 int value=yourage-studentlist.get(near).getage(); 101 System.out.println(""+studentlist.get(near)); 102 break; 103 case "5 ": 104 isTrue = false; 105 System.out.println("退出程序!"); 106 break; 107 default: 108 System.out.println("输入有误"); 109 110 } 111 } 112 } 113 public static int agenear(int age) { 114 int j=0,min=53,value=0,ok=0; 115 for (int i = 0; i < studentlist.size(); i++) 116 { 117 value=studentlist.get(i).getage()-age; 118 if(value<0) value=-value; 119 if (value<min) 120 { 121 min=value; 122 ok=i; 123 } 124 } 125 return ok; 126 } 127 }
1 public class Student implements Comparable<Student> { 2 3 private String name; 4 private String number ; 5 private String sex ; 6 private int age; 7 private String province; 8 9 public String getName() { 10 return name; 11 } 12 public void setName(String name) { 13 this.name = name; 14 } 15 public String getnumber() { 16 return number; 17 } 18 public void setnumber(String number) { 19 this.number = number; 20 } 21 public String getsex() { 22 return sex ; 23 } 24 public void setsex(String sex ) { 25 this.sex =sex ; 26 } 27 public int getage() { 28 29 return age; 30 } 31 public void setage(int age) { 32 // int a = Integer.parseInt(age); 33 this.age= age; 34 } 35 36 public String getprovince() { 37 return province; 38 } 39 public void setprovince(String province) { 40 this.province=province ; 41 } 42 43 public int compareTo(Student o) { 44 return this.name.compareTo(o.getName()); 45 } 46 47 public String toString() { 48 return name+" "+sex+" "+age+" "+number+" "+province+" "; 49 } 50 }
1 package ww; 2 import java.io.BufferedReader; 3 import java.io.File; 4 import java.io.FileInputStream; 5 import java.io.FileNotFoundException; 6 import java.io.IOException; 7 import java.io.InputStreamReader; 8 import java.util.ArrayList; 9 import java.util.Arrays; 10 import java.util.Collections; 11 import java.util.Scanner; 12 13 14 public class hhh{ 15 16 private static ArrayList<Person> Personlist1; 17 public static void main(String[] args) { 18 19 Personlist1 = new ArrayList<>(); 20 21 Scanner scanner = new Scanner(System.in); 22 File file = new File("E:\面向对象程序设计Java\实验\实验六\身份证号.txt"); 23 24 try { 25 FileInputStream F = new FileInputStream(file); 26 BufferedReader in = new BufferedReader(new InputStreamReader(F)); 27 String temp = null; 28 while ((temp = in.readLine()) != null) { 29 30 Scanner linescanner = new Scanner(temp); 31 32 linescanner.useDelimiter(" "); 33 String name = linescanner.next(); 34 String id = linescanner.next(); 35 String sex = linescanner.next(); 36 String age = linescanner.next(); 37 String place =linescanner.nextLine(); 38 Person Person = new Person(); 39 Person.setname(name); 40 Person.setid(id); 41 Person.setsex(sex); 42 int a = Integer.parseInt(age); 43 Person.setage(a); 44 Person.setbirthplace(place); 45 Personlist1.add(Person); 46 47 } 48 } catch (FileNotFoundException e) { 49 System.out.println("查找不到信息"); 50 e.printStackTrace(); 51 } catch (IOException e) { 52 System.out.println("信息读取有误"); 53 e.printStackTrace(); 54 } 55 boolean isTrue = true; 56 while (isTrue) { 57 System.out.println("******************************************"); 58 System.out.println("1:按姓名字典顺序输出信息;"); 59 System.out.println("2:查询最大年龄与最小年龄人员信息;"); 60 System.out.println("3:按省份找你的同乡;"); 61 System.out.println("4:输入你的年龄,查询年龄与你最近人的信息;"); 62 System.out.println("5:退出"); 63 System.out.println("******************************************"); 64 int type = scanner.nextInt(); 65 switch (type) { 66 case 1: 67 Collections.sort(Personlist1); 68 System.out.println(Personlist1.toString()); 69 break; 70 case 2: 71 72 int max=0,min=100;int j,k1 = 0,k2=0; 73 for(int i=1;i<Personlist1.size();i++) 74 { 75 j=Personlist1.get(i).getage(); 76 if(j>max) 77 { 78 max=j; 79 k1=i; 80 } 81 if(j<min) 82 { 83 min=j; 84 k2=i; 85 } 86 87 } 88 System.out.println("年龄最大:"+Personlist1.get(k1)); 89 System.out.println("年龄最小:"+Personlist1.get(k2)); 90 break; 91 case 3: 92 System.out.println("place?"); 93 String find = scanner.next(); 94 String place=find.substring(0,3); 95 String place2=find.substring(0,3); 96 for (int i = 0; i <Personlist1.size(); i++) 97 { 98 if(Personlist1.get(i).getbirthplace().substring(1,4).equals(place)) 99 { 100 System.out.println("你的同乡:"+Personlist1.get(i)); 101 } 102 } 103 104 break; 105 case 4: 106 System.out.println("年龄:"); 107 int yourage = scanner.nextInt(); 108 int close=ageclose(yourage); 109 int d_value=yourage-Personlist1.get(close).getage(); 110 System.out.println(""+Personlist1.get(close)); 111 112 break; 113 case 5: 114 isTrue = false; 115 System.out.println("再见!"); 116 break; 117 default: 118 System.out.println("输入有误"); 119 } 120 } 121 } 122 public static int ageclose(int age) { 123 int m=0; 124 int max=53; 125 int d_value=0; 126 int k=0; 127 for (int i = 0; i < Personlist1.size(); i++) 128 { 129 d_value=Personlist1.get(i).getage()-age; 130 if(d_value<0) d_value=-d_value; 131 if (d_value<max) 132 { 133 max=d_value; 134 k=i; 135 } 136 137 } return k; 138 139 } 140
1 package Second; 2 3 4 public class Person implements Comparable<Person> {
5 6 private String name; 7 private String id; 8 private int age; 9 private String sex; 10 private String birthplace;
11
12 13 public String getname() { 14 return name; 15 } 16 public void setname(String name) { 17 this.name = name; 18 } 19 public String getid() { 20 return id; 21 } 22 public void setid(String id) { 23 this.id= id; 24 } 25 public int getage() { 26 27 return age; 28 } 29 public void setage(int age) { 30 //int a = Integer.parseInt(age); 31 this.age= age; 32 } 33 public String getsex() { 34 return sex; 35 } 36 public void setsex(String sex) { 37 this.sex= sex; 38 } 39 public String getbirthplace() { 40 return birthplace; 41 } 42 public void setbirthplace(String birthplace) { 43 this.birthplace= birthplace; 44 } 45 46 public int compareTo(Person o) { 47 return this.name.compareTo(o.getname()); 48 49 } 50 51 public String toString() { 52 return name+" "+sex+" "+age+" "+id+" ";
结合使用体验对所运行程序提出完善建议;
l 各自运行合作伙伴实验十编程练习2,
1 package Zhao; 2 3 import java.io.FileNotFoundException; 4 import java.io.PrintWriter; 5 import java.util.Scanner; 6 7 //import org.w3c.dom.css.Counter; 8 9 10 public class Main{ 11 public static void main(String[] args) { 12 13 Scanner in = new Scanner(System.in); 14 counter Counter=new counter(); 15 PrintWriter output = null; 16 try { 17 output = new PrintWriter("result.txt"); 18 } catch (Exception e) { 19 //e.printStackTrace(); 20 } 21 int sum = 0; 22 23 for (int i = 1; i <=10; i++) { 24 int a = (int) Math.round(Math.random() * 100); 25 int b = (int) Math.round(Math.random() * 100); 26 int type = (int) Math.round(Math.random() * 4); 27 28 29 switch(type) 30 { 31 case 1: 32 33 System.out.println(i+": "+a+"/"+b+"="); 34 while(b== 0&& a%b!=0) 35 { 36 b = (int) Math.round(Math.random() * 100); 37 a = (int) Math.round(Math.random() * 100); 38 } 39 40 int c = in.nextInt(); 41 output.println(a+"/"+b+"="+c); 42 if (c == Counter.Chu(a, b)) 43 { 44 sum += 10; 45 System.out.println("恭喜答案正确!"); 46 } 47 else { 48 System.out.println("答案错误!"); 49 } 50 break; 51 52 case 2: 53 System.out.println(i+": "+a+"*"+b+"="); 54 int c1 = in.nextInt(); 55 output.println(a+"*"+b+"="+c1); 56 if (c1 == Counter.Cheng(a, b)) { 57 sum += 10; 58 System.out.println("恭喜答案正确!"); 59 } 60 else { 61 System.out.println("答案错误!"); 62 } 63 break; 64 case 3: 65 System.out.println(i+": "+a+"+"+b+"="); 66 int c2 = in.nextInt(); 67 output.println(a+"+"+b+"="+c2); 68 69 if (c2 == Counter.Jia(a, b)) { 70 sum += 10; 71 System.out.println("恭喜答案正确!"); 72 } 73 else { 74 System.out.println("答案错误!"); 75 } 76 break ; 77 78 79 case 4: 80 81 while (a < b) { 82 int x=0; 83 x=b; 84 b=a; 85 a=x; 86 } 87 System.out.println(i+": "+a+"-"+b+"="); 88 int c3 = in.nextInt(); 89 output.println(a+"-"+b+"="+c3); 90 if (c3 == Counter.Jian(a, b)) 91 { 92 sum += 10; 93 System.out.println("恭喜答案正确!"); 94 } 95 else { 96 System.out.println("答案错误!"); 97 } 98 break ; 99 100 } 101 102 } 103 System.out.println("成绩"+sum); 104 output.println("成绩:"+sum); 105 output.close(); 106 107 } 108 }
1 package Zhao; 2 3 4 public class counter<T>{ 5 private T a; 6 private T b; 7 8 public counter(T a, T b) { 9 this.a = a; 10 this.b = b; 11 } 12 13 public counter() { 14 // TODO Auto-generated constructor stub 15 } 16 17 public int Jia(int a,int b) 18 { 19 return a+b; 20 } 21 public int Jian(int a,int b) 22 { 23 return a-b; 24 25 26 } 27 public int Cheng(int a,int b) 28 { 29 return a*b; 30 } 31 public int Chu(int a,int b) 32 { 33 if (b!= 0 && a%b==0) 34 return a / b; 35 else 36 return 0; 37 38 } 39 40 41 }
结合使用体验对所运行程序提出完善建议;
实验十
1.没有全面考虑小学生的实际状况:减法算法结果可能出现负数的情况,以及除法的运算结果直接取整输出,都不符合小学生的学习范围;
2.编程过程中,关于变量的使用混乱问题;
3.结果没有输出到文件中;
l 采用结对编程方式,与学习伙伴合作完成实验九编程练习1;
1 package First; 2 import java.io.BufferedReader; 3 import java.io.File; 4 import java.io.FileInputStream; 5 import java.io.FileNotFoundException; 6 import java.io.IOException; 7 import java.io.InputStreamReader; 8 import java.util.ArrayList; 9 import java.util.Arrays; 10 import java.util.Collections; 11 import java.util.Scanner; 12 13 14 public class Search{ 15 16 private static ArrayList<Person> Personlist1; 17 public static void main(String[] args) { 18 19 Personlist1 = new ArrayList<>(); 20 21 Scanner scanner = new Scanner(System.in); 22 File file = new File("E:\面向对象程序设计Java\实验\实验六\身份证号.txt"); 23 24 try { 25 FileInputStream F = new FileInputStream(file); 26 BufferedReader in = new BufferedReader(new InputStreamReader(F)); 27 String temp = null; 28 while ((temp = in.readLine()) != null) { 29 30 Scanner linescanner = new Scanner(temp); 31 32 linescanner.useDelimiter(" "); 33 String name = linescanner.next(); 34 String id = linescanner.next(); 35 String sex = linescanner.next(); 36 String age = linescanner.next(); 37 String place =linescanner.nextLine(); 38 Person Person = new Person(); 39 Person.setname(name); 40 Person.setid(id); 41 Person.setsex(sex); 42 int a = Integer.parseInt(age); 43 Person.setage(a); 44 Person.setbirthplace(place); 45 Personlist1.add(Person); 46 47 } 48 } catch (FileNotFoundException e) { 49 System.out.println("查找不到信息"); 50 e.printStackTrace(); 51 } catch (IOException e) { 52 System.out.println("信息读取有误"); 53 e.printStackTrace(); 54 } 55 boolean isTrue = true; 56 while (isTrue) { 57 System.out.println("******************************************"); 58 System.out.println("1:按姓名字典顺序输出信息;"); 59 System.out.println("2:查询最大年龄与最小年龄人员信息;"); 60 System.out.println("3:按省份找你的同乡;"); 61 System.out.println("4:输入你的年龄,查询年龄与你最近人的信息;"); 62 System.out.println("5:退出"); 63 System.out.println("******************************************"); 64 int type = scanner.nextInt(); 65 switch (type) { 66 case 1: 67 Collections.sort(Personlist1); 68 System.out.println(Personlist1.toString()); 69 break; 70 case 2: 71 72 int max=0,min=100;int j,k1 = 0,k2=0; 73 for(int i=1;i<Personlist1.size();i++) 74 { 75 j=Personlist1.get(i).getage(); 76 if(j>max) 77 { 78 max=j; 79 k1=i; 80 } 81 if(j<min) 82 { 83 min=j; 84 k2=i; 85 } 86 87 } 88 System.out.println("年龄最大:"+Personlist1.get(k1)); 89 System.out.println("年龄最小:"+Personlist1.get(k2)); 90 break; 91 case 3: 92 System.out.println("place?"); 93 String find = scanner.next(); 94 String place=find.substring(0,3); 95 String place2=find.substring(0,3); 96 for (int i = 0; i <Personlist1.size(); i++) 97 { 98 if(Personlist1.get(i).getbirthplace().substring(1,4).equals(place)) 99 { 100 System.out.println("你的同乡:"+Personlist1.get(i)); 101 } 102 } 103 104 break; 105 case 4: 106 System.out.println("年龄:"); 107 int yourage = scanner.nextInt(); 108 int close=ageclose(yourage); 109 int d_value=yourage-Personlist1.get(close).getage(); 110 System.out.println(""+Personlist1.get(close)); 111 112 break; 113 case 5: 114 isTrue = false; 115 System.out.println("再见!"); 116 break; 117 default: 118 System.out.println("输入有误"); 119 } 120 } 121 } 122 public static int ageclose(int age) { 123 int m=0; 124 int max=53; 125 int d_value=0; 126 int k=0; 127 for (int i = 0; i < Personlist1.size(); i++) 128 { 129 d_value=Personlist1.get(i).getage()-age; 130 if(d_value<0) d_value=-d_value; 131 if (d_value<max) 132 { 133 max=d_value; 134 k=i; 135 } 136 137 } return k; 138 139 } 140 }
1 package FFF; 2 3 4 public class Person implements Comparable<Person> { 5
6
7 private String name; 8 private String id; 9 private int age; 10 private String sex; 11 private String birthplace; 12 13 public String getname() { 14 return name; 15 } 16 public void setname(String name) { 17 this.name = name; 18 } 19 public String getid() { 20 return id; 21 } 22 public void setid(String id) { 23 this.id= id; 24 } 25 public int getage() { 26 27 return age; 28 } 29 public void setage(int age) { 30 //int a = Integer.parseInt(age); 31 this.age= age; 32 } 33 public String getsex() { 34 return sex; 35 } 36 public void setsex(String sex) { 37 this.sex= sex; 38 } 39 public String getbirthplace() { 40 return birthplace; 41 } 42 public void setbirthplace(String birthplace) { 43 this.birthplace= birthplace; 44 } 45 46 public int compareTo(Person o) { 47 return this.name.compareTo(o.getname()); 48 49 } 50 51 public String toString() { 52 return name+" "+sex+" "+age+" "+id+" ";
采用结对编程方式,与学习伙伴合作完成实验十编程练习2。
1 package PP; 2 3 import java.io.FileNotFoundException; 4 import java.io.IOException; 5 import java.io.PrintWriter; 6 import java.util.Scanner; 7 public class Main { 8 9 public static void main(String[] args) { 10 Scanner in = new Scanner(System.in); 11 counter min=new counter(); 12 PrintWriter out = null; 13 try { 14 out = new PrintWriter("result.txt"); 15 int sum = 0; 16 for (int i = 1; i <=10; i++) { 17 int a = (int) Math.round(Math.random() * 100); 18 int b = (int) Math.round(Math.random() * 100); 19 int menu = (int) Math.round(Math.random() * 3); 20 switch (menu) { 21 case 0: 22 System.out.println(i+":"+a + "+" + b + "="); 23 int c1 = in.nextInt(); 24 out.println(a + "+" + b + "=" + c1); 25 if (c1 == (a + b)) { 26 sum += 10; 27 System.out.println("恭喜答案正确"); 28 } else { 29 System.out.println("抱歉,答案错误"); 30 } 31 break; 32 case 1: 33 while (a < b) { 34 b = (int) Math.round(Math.random() * 100); 35 } 36 System.out.println(i+":"+a + "-" + b + "="); 37 int c2 = in.nextInt(); 38 out.println(a + "-" + b + "=" + c2); 39 if (c2 == (a - b)) { 40 sum += 10; 41 System.out.println("恭喜答案正确"); 42 } else { 43 System.out.println("抱歉,答案错误"); 44 } 45 46 break; 47 case 2: 48 System.out.println(i+":"+a + "*" + b + "="); 49 int c3 = in.nextInt(); 50 out.println(a + "*" + b + "=" + c3); 51 if (c3 == a * b) { 52 sum += 10; 53 System.out.println("恭喜答案正确"); 54 } else { 55 System.out.println("抱歉,答案错误"); 56 } 57 58 break; 59 case 3: 60 while(b == 0){ 61 b = (int) Math.round(Math.random() * 100); 62 } 63 while(a % b != 0){ 64 a = (int) Math.round(Math.random() * 100); 65 66 } 67 System.out.println(i+":"+a + "/" + b + "="); 68 int c4 = in.nextInt(); 69 if (c4 == a / b) { 70 sum += 10; 71 System.out.println("恭喜,答案正确"); 72 } else { 73 System.out.println("抱歉,答案错误"); 74 } 75 76 break; 77 } 78 } 79 System.out.println("你的得分为" + sum); 80 out.println("你的得分为" + sum); 81 out.close(); 82 } catch (FileNotFoundException e) { 83 e.printStackTrace(); 84 } 85 } 86 }
1 package PP; 2 3 public class counter<T> { 4 private T a; 5 private T b; 6 public counter() { 7 a=null; 8 b=null; 9 } 10 public counter(T a,T b) { 11 this.a=a; 12 this.b=b; 13 } 14 public int count1(int a,int b) { 15 return a+b; 16 } 17 public int count2(int a,int b) { 18 return a-b; 19 } 20 public int count3(int a,int b) { 21 return a*b; 22 } 23 public int count4(int a,int b) { 24 return a/b; 25 } 26 }
实验总结:
通过本周学习,我进一步复习了一些有关数据结构的知识,另外初步了解了java集合类,也了解了Vector类,Stack类以及Hashtable类。除此以外,此次实验第一次采用结对编程的方法,通过和合作伙伴互相运行程序,相互讨论交流,从中学到了很多东西。希望以后多采取这种方法,在合作中互相学习进步。