Question

刚入门C++，请问下面这个问题怎么解决，下面是源代码

#include<iostream>using namespace std;class Book{private: char bookname; double price; int number;public: void book(char a,double b,int c) { this->bookname=a; this->price=b; this->number=c; } void dispaly() { cout<<bookname<<" "<<price<<" "<<number<<endl; } void borrow() { this->number--; } void restore() { this->number++; }}int main(){ char name[20]="C++"; Book book1(name,23.5,3); strcpy(name,"Data Structure"); Book book2(name,28.8,7); book1.borrow(); book1.display(); book2.restore(); book2.display(); return 0;}

Answer 1

同意以上代码

Answer 2

#include<iostream>
using namespace std;
class Book
{
    private: 
    string bookname; 
    double price; 
    int number;
    public: 
    Book(string a,double b,int c) 
    { 
        this->bookname=a; 
        this->price=b; 
        this->number=c; 
    } 
    void display() 
    { 
        cout<<bookname<<" "<<price<<" "<<number<<endl; 
    } 
    void borrow() 
    { 
        this->number--; 
    } 
    void restore() 
    { 
        this->number++; 
    }
};
int main()
{ 
    string name = "C++"; 
    Book book1(name,23.1,3); 
    name+="Data Structure";
    //strcpy(name,"Data Structure"); 
    Book book2(name,28.8,7); 
    book1.borrow(); 
    book1.display(); 
    book2.restore(); 
    book2.display(); 
    cout << name << endl;
    return 0;
}

记得给个赞同、推荐

追问

这是题目要求，必须要定义一个数组存储name ……

追答

#include<iostream>
#include <cstring>
using namespace std;
class Book
{
    private: 
    char * bookname; 
    double price; 
    int number;
    public: 
    Book(char * a,double b,int c) 
    { 
        this->bookname=a; 
        this->price=b; 
        this->number=c; 
    } 
    void display() 
    { 
        cout<<bookname<<" "<<price<<" "<<number<<endl; 
    } 
    void borrow() 
    { 
        this->number--; 
    } 
    void restore() 
    { 
        this->number++; 
    }
};
int main()
{ 
    char name[20] = "C++"; 
    Book book1(name,23.1,3); 
    //name+="Data Structure";
    strcpy(name,"Data Structure"); 
    Book book2(name,28.8,7); 
    book1.borrow(); 
    book1.display(); 
    book2.restore(); 
    book2.display(); 
    //cout << name << endl;
    return 0;
}

追问

为啥会出现这种错误。。。。。。

追答

建议您学习一下截图，别拍照。。

追问

主要截图没办法截出错误原因

追答

你换一个编译器，这个可能是因为字符集的关系

Answer 3

#include<iostream>
#include<cstring>

using namespace std;

class Book
{
public:
Book(char *nm,float pr,int num):price(pr),number(num)
{
bookname=new char[strlen(nm)+1];
strcpy(bookname,nm);
}
~Book()
{
if(bookname)
delete [] bookname;
}
void borrow()
{
if(number>0)
{
number--;
cout<<number<<endl;
}
else
cout<<"当前存书数量已为0"<<endl;
}
void restore()
{
number++;
cout<<number<<endl;
}
void display() const
{
cout<<bookname<<" "<<price<<" "<<number<<endl;
}
private:
char *bookname;
float price;
int number;
};

int main()
{
char name[20]="C++";
Book book1(name,23.5,3);
strcpy(name,"Data Structure");
Book book2(name,28.8,7);
book1.borrow();
book1.display();
book2.restore();
book2.display();
return 0;
}

Answer 4

有如下错误：
①每个打印（print）函数少了右大括号｝。
②定义的字符串要初始化。
③Postgrad p(d);Data d(na);Student s(i);Teacher t(sa);这句话中的Data d(na)的对象d的名称与字符串变量重名