实验十一 集合
实验时间 2018-11-8
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;
掌握Vetor、Stack、Hashtable三个类的用途及常用API。
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实验结果1
实验结果2
实验结果3
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;
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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。
package linkedList; 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"); // merge the words from b into a 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); // remove every second word from b bIter = b.iterator(); while (bIter.hasNext()) { bIter.next(); // skip one element if (bIter.hasNext()) { bIter.next(); // skip next element bIter.remove(); // remove that element } } System.out.println(b); // bulk operation: remove all words in b from a a.removeAll(b); System.out.println(a); } }
测试程序3:
l 运行SetDemo程序,结合运行结果理解程序;
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"); // DUPLICATE h.add("Three"); Iterator it = h.iterator(); while (it.hasNext()) { System.out.println(it.next()); } } } |
l 在Elipse环境下调试教材365页程序9-2,结合运行结果理解程序;了解HashSet类的用途及常用API。
1 package set; 2 3 import java.util.*; 4 5 /** 6 * This program uses a set to print all unique words in System.in. 7 * @version 1.12 2015-06-21 8 * @author Cay Horstmann 9 */ 10 public class SetTest 11 { 12 public static void main(String[] args) 13 { 14 Set<String> words = new HashSet<>(); // HashSet implements Set 15 long totalTime = 0; 16 17 try (Scanner in = new Scanner(System.in)) 18 { 19 while (in.hasNext()) 20 { 21 String word = in.next(); 22 long callTime = System.currentTimeMillis(); 23 words.add(word); 24 callTime = System.currentTimeMillis() - callTime; 25 totalTime += callTime; 26 } 27 } 28 29 Iterator<String> iter = words.iterator(); 30 for (int i = 1; i <= 20 && iter.hasNext(); i++) 31 System.out.println(iter.next()); 32 System.out.println(". . ."); 33 System.out.println(words.size() + " distinct words. " + totalTime + " milliseconds."); 34 } 35 }
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。
1 package treeSet; 2 3 import java.util.*; 4 5 /** 6 * An item with a description and a part number. 7 */ 8 public class Item implements Comparable<Item> 9 { 10 private String description; 11 private int partNumber; 12 13 /** 14 * Constructs an item. 15 * 16 * @param aDescription 17 * the item's description 18 * @param aPartNumber 19 * the item's part number 20 */ 21 public Item(String aDescription, int aPartNumber) 22 { 23 description = aDescription; 24 partNumber = aPartNumber; 25 } 26 27 /** 28 * Gets the description of this item. 29 * 30 * @return the description 31 */ 32 public String getDescription() 33 { 34 return description; 35 } 36 37 public String toString() 38 { 39 return "[description=" + description + ", partNumber=" + partNumber + "]"; 40 } 41 42 public boolean equals(Object otherObject) 43 { 44 if (this == otherObject) return true; 45 if (otherObject == null) return false; 46 if (getClass() != otherObject.getClass()) return false; 47 Item other = (Item) otherObject; 48 return Objects.equals(description, other.description) && partNumber == other.partNumber; 49 } 50 51 public int hashCode() 52 { 53 return Objects.hash(description, partNumber); 54 } 55 56 public int compareTo(Item other) 57 { 58 int diff = Integer.compare(partNumber, other.partNumber); 59 return diff != 0 ? diff : description.compareTo(other.description); 60 } 61 }
1 package treeSet; 2 3 import java.util.*; 4 5 /** 6 * This program sorts a set of item by comparing their descriptions. 7 * @version 1.12 2015-06-21 8 * @author Cay Horstmann 9 */ 10 public class TreeSetTest 11 { 12 public static void main(String[] args) 13 { 14 SortedSet<Item> parts = new TreeSet<>(); 15 parts.add(new Item("Toaster", 1234)); 16 parts.add(new Item("Widget", 4562)); 17 parts.add(new Item("Modem", 9912)); 18 System.out.println(parts); 19 20 NavigableSet<Item> sortByDescription = new TreeSet<>( 21 Comparator.comparing(Item::getDescription)); 22 23 sortByDescription.addAll(parts); 24 System.out.println(sortByDescription); 25 } 26 }
测试程序4:
使用JDK命令运行HashMapDemo程序,结合程序运行结果理解程序;
import java.util.*; public class HashMapDemo { public static void main(String[] argv) { HashMap h = new HashMap(); // The hash maps from company name to address. 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); } } |
实验结果:
l 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;
l 了解HashMap、TreeMap两个类的用途及常用API。
1 package map; 2 3 import java.util.*; 4 5 /** 6 * This program demonstrates the use of a map with key type String and value type Employee. 7 * @version 1.12 2015-06-21 8 * @author Cay Horstmann 9 */ 10 public class MapTest 11 { 12 public static void main(String[] args) 13 { 14 Map<String, Employee> staff = new HashMap<>(); 15 staff.put("144-25-5464", new Employee("Amy Lee")); 16 staff.put("567-24-2546", new Employee("Harry Hacker")); 17 staff.put("157-62-7935", new Employee("Gary Cooper")); 18 staff.put("456-62-5527", new Employee("Francesca Cruz")); 19 20 // print all entries 21 22 System.out.println(staff); 23 24 // remove an entry 25 26 staff.remove("567-24-2546"); 27 28 // replace an entry 29 30 staff.put("456-62-5527", new Employee("Francesca Miller")); 31 32 // look up a value 33 34 System.out.println(staff.get("157-62-7935")); 35 36 // iterate through all entries 37 38 staff.forEach((k, v) -> 39 System.out.println("key=" + k + ", value=" + v)); 40 } 41 }
1 package map; 2 3 /** 4 * A minimalist employee class for testing purposes. 5 */ 6 public class Employee 7 { 8 private String name; 9 private double salary; 10 11 /** 12 * Constructs an employee with $0 salary. 13 * @param n the employee name 14 */ 15 public Employee(String name) 16 { 17 this.name = name; 18 salary = 0; 19 } 20 21 public String toString() 22 { 23 return "[name=" + name + ", salary=" + salary + "]"; 24 } 25 }
实验结果:
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;
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 package test1; 2 3 import java.io.BufferedReader; 4 import java.io.File; 5 import java.io.FileInputStream; 6 import java.io.FileNotFoundException; 7 import java.io.IOException; 8 import java.io.InputStreamReader; 9 import java.util.ArrayList; 10 import java.util.Collections; 11 import java.util.Scanner; 12 13 public class Main{ 14 private static ArrayList<Student> studentlist; 15 public static void main(String[] args) { 16 studentlist = new ArrayList<>(); 17 Scanner scanner = new Scanner(System.in); 18 File file = new File("F:\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("学生信息文件找不到"); 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,输入正确格式的选项"); 53 System.out.println("A.按姓名字典排序"); 54 System.out.println("B.输出年龄最大和年龄最小的人"); 55 System.out.println("C.寻找老乡"); 56 System.out.println("D.寻找年龄相近的人"); 57 System.out.println("F.退出"); 58 String m = scanner.next(); 59 switch (m) { 60 case "A": 61 Collections.sort(studentlist); 62 System.out.println(studentlist.toString()); 63 break; 64 case "B": 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 "C": 86 System.out.println("老家?"); 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("老乡"+studentlist.get(i)); 93 } 94 break; 95 96 case "D": 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 "F": 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,k=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 k=i; 123 } 124 } 125 return k; 126 } 127 128 }
1 package test1; 2 3 public class Student implements Comparable<Student> { 4 5 private String name; 6 private String number ; 7 private String sex ; 8 private int age; 9 private String province; 10 11 public String getName() { 12 return name; 13 } 14 public void setName(String name) { 15 this.name = name; 16 } 17 public String getnumber() { 18 return number; 19 } 20 public void setnumber(String number) { 21 this.number = number; 22 } 23 public String getsex() { 24 return sex ; 25 } 26 public void setsex(String sex ) { 27 this.sex =sex ; 28 } 29 public int getage() { 30 31 return age; 32 } 33 public void setage(int age) { 34 // int a = Integer.parseInt(age); 35 this.age= age; 36 } 37 38 public String getprovince() { 39 return province; 40 } 41 public void setprovince(String province) { 42 this.province=province ; 43 } 44 45 public int compareTo(Student o) { 46 return this.name.compareTo(o.getName()); 47 } 48 49 public String toString() { 50 return name+" "+sex+" "+age+" "+number+" "+province+" "; 51 } 52 }
完善建议:无
l 各自运行合作伙伴实验十编程练习2,结合使用体验对所运行程序提出完善建议;
1 package shiyan; 2 import java.util.Scanner; 3 import java.io.FileNotFoundException; 4 import java.io.PrintWriter; 5 6 public class Main { 7 public static void main(String[] args) { 8 Scanner in=new Scanner(System.in); 9 PrintWriter output = null; 10 try { 11 output = new PrintWriter("E:/test.txt"); 12 } catch (FileNotFoundException e) { 13 // TODO 自动生成的 catch 块 14 System.out.println("文件输出失败"); 15 e.printStackTrace(); 16 } 17 int sum=0; 18 jisuanji js=new jisuanji(); 19 for (int i = 0; i < 10; i++) { 20 int a = (int) Math.round(Math.random() * 100); 21 int b = (int) Math.round(Math.random() * 100); 22 int n = (int) Math.round(Math.random() * 4 ); 23 24 switch(n) 25 { 26 case 1: 27 System.out.println(a+"/"+b+"="); 28 while(b==0){ 29 b = (int) Math.round(Math.random() * 100); 30 } 31 while(a%b!=0) { 32 a = (int) Math.round(Math.random() * 100); 33 b = (int) Math.round(Math.random() * 100); 34 } 35 double c = in.nextDouble(); 36 output.println(a+"/"+b+"="+c); 37 if (c == js.chu(a,b)) { 38 sum += 10; 39 System.out.println("答案正确"); 40 } 41 else { 42 System.out.println("答案错误"); 43 } 44 45 break; 46 47 case 2: 48 System.out.println(a+"*"+b+"="); 49 int c1 = in.nextInt(); 50 output.println(a+"*"+b+"="+c1); 51 if (c1 == js.chen(a, b)) { 52 sum += 10; 53 System.out.println("答案正确"); 54 } 55 else { 56 System.out.println("答案错误"); 57 } 58 break; 59 case 3: 60 System.out.println(a+"+"+b+"="); 61 int c2 = in.nextInt(); 62 output.println(a+"+"+b+"="+c2); 63 if (c2 == js.jia(a, b)) { 64 sum += 10; 65 System.out.println("答案正确"); 66 } 67 else { 68 System.out.println("答案错误"); 69 } 70 71 break ; 72 case 4: 73 System.out.println(a+"-"+b+"="); 74 while(a<b) { 75 a = (int) Math.round(Math.random() * 100); 76 b = (int) Math.round(Math.random() * 100); 77 } 78 int c3 = in.nextInt(); 79 output.println(a+"-"+b+"="+c3); 80 if (c3 == js.jian(a,b)) { 81 sum += 10; 82 System.out.println("答案正确"); 83 } 84 else { 85 System.out.println("答案错误"); 86 } 87 break ; 88 89 } 90 91 } 92 System.out.println("成绩"+sum); 93 output.println("成绩:"+sum); 94 output.close(); 95 } 96 }
1 package shiyan; 2 3 public class jisuanji<T> { 4 private T a; 5 private T b; 6 public jisuanji() { 7 a=null; 8 b=null; 9 } 10 public jisuanji(T a,T b) { 11 this.a=a; 12 this.b=b; 13 } 14 public int jia(int a,int b) 15 { 16 return a+b; 17 } 18 public int jian(int a,int b) 19 { 20 return a-b; 21 } 22 public int chen(int a,int b) 23 { 24 return a*b; 25 } 26 public int chu(int a,int b) 27 { 28 if(b!=0&&a%b==0) 29 return a/b; 30 else 31 return 0; 32 } 33 }
完善建议:jisuanji类的除法的一些限制条件多余,可以不写,简化代码。
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 test1; 2 3 import java.io.BufferedReader; 4 import java.io.File; 5 import java.io.FileInputStream; 6 import java.io.FileNotFoundException; 7 import java.io.IOException; 8 import java.io.InputStreamReader; 9 import java.util.ArrayList; 10 import java.util.Collections; 11 import java.util.Scanner; 12 13 public class Main{ 14 private static ArrayList<Student> studentlist; 15 public static void main(String[] args) { 16 studentlist = new ArrayList<>(); 17 Scanner scanner = new Scanner(System.in); 18 File file = new File("F:\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("学生信息文件找不到"); 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,输入正确格式的选项"); 53 System.out.println("A.按姓名字典排序"); 54 System.out.println("B.输出年龄最大和年龄最小的人"); 55 System.out.println("C.寻找老乡"); 56 System.out.println("D.寻找年龄相近的人"); 57 System.out.println("F.退出"); 58 String m = scanner.next(); 59 switch (m) { 60 case "A": 61 Collections.sort(studentlist); 62 System.out.println(studentlist.toString()); 63 break; 64 case "B": 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 "C": 86 System.out.println("老家?"); 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("老乡"+studentlist.get(i)); 93 } 94 break; 95 96 case "D": 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 "F": 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,k=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 k=i; 123 } 124 } 125 return k; 126 } 127 128 }
1 package test1; 2 3 public class Student implements Comparable<Student> { 4 5 private String name; 6 private String number ; 7 private String sex ; 8 private int age; 9 private String province; 10 11 public String getName() { 12 return name; 13 } 14 public void setName(String name) { 15 this.name = name; 16 } 17 public String getnumber() { 18 return number; 19 } 20 public void setnumber(String number) { 21 this.number = number; 22 } 23 public String getsex() { 24 return sex ; 25 } 26 public void setsex(String sex ) { 27 this.sex =sex ; 28 } 29 public int getage() { 30 31 return age; 32 } 33 public void setage(int age) { 34 // int a = Integer.parseInt(age); 35 this.age= age; 36 } 37 38 public String getprovince() { 39 return province; 40 } 41 public void setprovince(String province) { 42 this.province=province ; 43 } 44 45 public int compareTo(Student o) { 46 return this.name.compareTo(o.getName()); 47 } 48 49 public String toString() { 50 return name+" "+sex+" "+age+" "+number+" "+province+" "; 51 } 52 }
l 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 shiyan; 2 import java.util.Scanner; 3 import java.io.FileNotFoundException; 4 import java.io.PrintWriter; 5 6 public class Main { 7 public static void main(String[] args) { 8 Scanner in=new Scanner(System.in); 9 PrintWriter output = null; 10 try { 11 output = new PrintWriter("E:/test.txt"); 12 } catch (FileNotFoundException e) { 13 // TODO 自动生成的 catch 块 14 System.out.println("文件输出失败"); 15 e.printStackTrace(); 16 } 17 int sum=0; 18 jisuanji js=new jisuanji(); 19 for (int i = 0; i < 10; i++) { 20 int a = (int) Math.round(Math.random() * 100); 21 int b = (int) Math.round(Math.random() * 100); 22 int n = (int) Math.round(Math.random() * 4 ); 23 24 switch(n) 25 { 26 case 1: 27 System.out.println(a+"/"+b+"="); 28 while(b==0){ 29 b = (int) Math.round(Math.random() * 100); 30 } 31 while(a%b!=0) { 32 a = (int) Math.round(Math.random() * 100); 33 b = (int) Math.round(Math.random() * 100); 34 } 35 double c = in.nextDouble(); 36 output.println(a+"/"+b+"="+c); 37 if (c == js.chu(a,b)) { 38 sum += 10; 39 System.out.println("答案正确"); 40 } 41 else { 42 System.out.println("答案错误"); 43 } 44 45 break; 46 47 case 2: 48 System.out.println(a+"*"+b+"="); 49 int c1 = in.nextInt(); 50 output.println(a+"*"+b+"="+c1); 51 if (c1 == js.chen(a, b)) { 52 sum += 10; 53 System.out.println("答案正确"); 54 } 55 else { 56 System.out.println("答案错误"); 57 } 58 break; 59 case 3: 60 System.out.println(a+"+"+b+"="); 61 int c2 = in.nextInt(); 62 output.println(a+"+"+b+"="+c2); 63 if (c2 == js.jia(a, b)) { 64 sum += 10; 65 System.out.println("答案正确"); 66 } 67 else { 68 System.out.println("答案错误"); 69 } 70 71 break ; 72 case 4: 73 System.out.println(a+"-"+b+"="); 74 while(a<b) { 75 a = (int) Math.round(Math.random() * 100); 76 b = (int) Math.round(Math.random() * 100); 77 } 78 int c3 = in.nextInt(); 79 output.println(a+"-"+b+"="+c3); 80 if (c3 == js.jian(a,b)) { 81 sum += 10; 82 System.out.println("答案正确"); 83 } 84 else { 85 System.out.println("答案错误"); 86 } 87 break ; 88 89 } 90 91 } 92 System.out.println("成绩"+sum); 93 output.println("成绩:"+sum); 94 output.close(); 95 } 96 }
1 package shiyan; 2 3 public class jisuanji<T> { 4 private T a; 5 private T b; 6 public jisuanji() { 7 a=null; 8 b=null; 9 } 10 public jisuanji(T a,T b) { 11 this.a=a; 12 this.b=b; 13 } 14 public int jia(int a,int b) 15 { 16 return a+b; 17 } 18 public int jian(int a,int b) 19 { 20 return a-b; 21 } 22 public int chen(int a,int b) 23 { 24 return a*b; 25 } 26 public int chu(int a,int b) 27 { 28 if(b!=0&&a%b==0) 29 return a/b; 30 else 31 return 0; 32 } 33 }
本周实验总结:
学会了一些简单的数据结构,例如链,栈,队列,散列表等。还有Java的集合框架,集合类的内容。
复习了前面学过的知识细节,例如强制转换类型时进行判断的instanceof语句。初步体会了合作编程,互相提高的过程和乐趣。