內(nèi)蒙古科技大學面向對象的程序設計實驗6靜態(tài)成員和友元

1、內(nèi)蒙古科技大學面向對象的程序設計實驗報告課程名稱：面向對象的程序設計姓名：陳偉光實驗名稱：靜態(tài)成員和友元學號：1567159118任課教師：劉月峰專業(yè)：軟件工程指導教師：劉月峰班級：15-軟件一班一、實驗目的1理解靜態(tài)成員（靜態(tài)數(shù)據(jù)成員、靜態(tài)成員函數(shù)）的作用與使用；2理解友元（友元函數(shù)、友元類）的作用于使用。二、實驗環(huán)境編譯器：Visual C+ 6.0.操作系統(tǒng)：Windows 7旗艦版三、實驗內(nèi)容二、實驗內(nèi)容2.1練習（一）：1理解下面的程序，并在VC+6.0下運行查看結果，回答程序后面的問題。#include #include class CStudentpublic:CStudent(

2、char *n, int a);CStudent();static void SetAge(int age);private:char *name;int age;static int nTotalObj;int CStudent:nTotalObj = 0;CStudent:CStudent(char *n, int a):age(a)int nLen = strlen(n);name = new charnLen+1;strcpy(name,n);namenLen = 0;nTotalObj+;CStudent:CStudent()delete name;nTotalObj-;void C

3、Student:SetAge(int age)this-age = age;void main()CStudent stu1(張三,25);CStudent str2(李四,26);coutCStudent:nTotalObj=CStudent:nTotalObjendl;問題一：以上程序編譯能通過嗎，為什么？問題二：成員變量nTotalObj在程序中起什么作用，它是如何實現(xiàn)的？問題三：如果規(guī)定該程序的主函數(shù)和類CStudent中的成員變量的屬性不允許改變，應該如何改正該程序？2理解下面的程序，并在VC+6.0下運行查看結果，回答程序后面的問題。#include #include class

4、CStudentpublic:CStudent(char *n, int a);CStudent();private:char *name;int age;CStudent:CStudent(char *n, int a):age(a)int nLen = strlen(n);name = new charnLen+1;strcpy(name,n);namenLen = 0;CStudent:CStudent()delete name;class CTeacherpublic:CTeacher(char *tn, int ta);CTeacher();void SetStuAge(int a)

5、;private:char *name;int age;CStudent stu;CTeacher:CTeacher(char *tn, int ta):age(ta)int nLen = strlen(tn);name = new charnLen+1;strcpy(name,tn);namenLen = 0;CTeacher:CTeacher()delete name;void CTeacher:SetStuAge(int a)stu.age = a;void main()CStudent stu(張三,25);CTeacher tea(李四,26);問題一：以上程序有兩大錯誤，試指出來，

6、并改正之？2.2練習（二）：1某商店經(jīng)銷一種貨物。貨物成箱購進，成箱賣出，購進和賣出時以重量為單位，各箱的重量不一樣，因此，商店需要記錄下貨物庫存的總重量。試用C+模擬商店貨物購進和賣出的情況。（提示：將總重量定義為靜態(tài)成員）四、實驗過程練習1 題目提供源代碼如下編譯結果如下分析之后得出結論首先靜態(tài)成員函數(shù)SetAge中不可以使用指針，也不可以直接使用非靜態(tài)數(shù)據(jù)成員age 此處應該使用對象名或者類名間接引用age其次nTotalObj為私有屬性，不可以直接訪問，且題目要求不可以修改其屬性，則添加一個成員函數(shù)，使其返回值等于nTotalObj,則代替了原先nTotalObj的功能修改之后的代碼如

7、下然后再次編譯運行結果如下運行結果正確，且不影響nTotalObj的計數(shù)器功能，代碼修改正確練習2題目提供源代碼如下編譯之后結果如下分析錯誤原因有兩點錯誤1 CTeacher類中的成員函數(shù)SetStuAge不能直接訪問CStudent類內(nèi)嵌成員stu的數(shù)據(jù)成員age錯誤2 CTeacher類構造函數(shù)的初始化含有錯誤,內(nèi)嵌對象stu的數(shù)據(jù)成員也應該包含在內(nèi)修改之后代碼如下運行結果如下成功運行，修改正確練習3根據(jù)題意，所編寫代碼如下嘗試測試運行結果該代碼包含題目要求的所有功能，運行完畢五、實驗總結實驗源代碼:練習（一）/修改之后代碼#include #include class CStudentp

8、ublic:CStudent(char *n, int a);CStudent();static void SetAge(CStudent stuN);static int CSnTota10bj();private:char *name;int age;static int nTotalObj;int CStudent:nTotalObj = 0;CStudent:CStudent(char *n, int a):age(a)int nLen = strlen(n);name = new charnLen+1;strcpy(name,n);namenLen = 0;nTotalObj+;CS

9、tudent:CStudent()delete name;nTotalObj-;int CStudent:CSnTota10bj()int n;n=nTotalObj;return n;void CStudent:SetAge(CStudent stuN)int a;stuN.age = a;void main()CStudent stu1(張三,25);CStudent str2(李四,26);coutCStudent:nTotalObj=CStudent:CSnTota10bj()endl;練習（二）#include #include class CStudentpublic:CStude

10、nt(char *n, int a);CStudent();private:char *name;public:int age;CStudent:CStudent(char *n, int a):age(a)int nLen = strlen(n);name = new charnLen+1;strcpy(name,n);namenLen = 0;CStudent:CStudent()delete name;class CTeacherpublic:CTeacher(char *tn,int ta,char *sn,int sa);CTeacher();void SetStuAge(int a

11、);private:char *name;int age;CStudent stu;CTeacher:CTeacher(char *tn,int ta,char *sn=noname,int sa=0):age(ta),stu(sn,sa)int nLen = strlen(tn);name = new charnLen+1;strcpy(name,tn);namenLen = 0;CTeacher:CTeacher()delete name;void CTeacher:SetStuAge(int a)stu.age = a;void main()CStudent stu(張三,25);CTe

12、acher tea(李四,26);/*錯誤1 CTeacher類中的成員函數(shù)SetStuAge不能直接訪問CStudent類內(nèi)嵌成員stu的數(shù)據(jù)成員age錯誤2 CTeacher類構造函數(shù)的初始化含有錯誤,內(nèi)嵌對象stu的數(shù)據(jù)成員也應該包含在內(nèi)*/練習（三）#include class Goodsprivate:int weight;static int totalWeight;public:Goods(int wei);static void PrintTotalWeight();void sell();void buy();int Goods:totalWeight = 0;Goods:G

13、oods(int twei)totalWeight = twei;cout初始總重量為:totalWeightendl;void Goods:PrintTotalWeight()cout總重量為:Goods:totalWeightendl;void Goods:buy()cout購入endl;coutweight;Goods:totalWeight += weight;weight= 0;void Goods:sell()cout售出endl;coutweight;Goods:totalWeight -= weight;weight= 0;void main()int twei=0;int swit=1;cout請設置初設總重量twei;Goods goods1(twei);while(swit)