Question

在Class Dim中我创建了数组G，我想将它传递给派生类PHYS_FIELD。它不是输出（0..9）而是给出（0..0）。我意识到它只是G的新副本，但我不知道如何正确地做到这一点。

#ifndef ARR1_H #define ARR1_H #include<iostream> using namespace std; template <class T> class arr1 { public: T* data; size_t size; arr1(const size_t isize) { size=isize; data = new T[size]; } T & operator ()(size_t const index) { return data[index]; } }; #endif /*ARR1_H */：

dim.h

#ifndef DIM_H #define DIM_H #include "arr1.h" class DIM { public: DIM(); protected: int N; }; #endif /* DIM_H */：

dim.cpp

#include "arr1.h" #include "dim.h" using namespace std; DIM :: DIM() { N=10; arr1<double> G(N); for (int i=0; i<N; i++) G(i)=i; };：

phys_field.h

#ifndef PHYS_FIELD_H #define PHYS_FIELD_H #include "dim.h" #include "arr1.h" class PHYS_FIELD : public DIM { public: PHYS_FIELD(); arr1<double> G; }; #endif /* PHYS__FIELD_H */：

phys_field.cpp

#include "dim.h" #include "phys_field.h" #include <arr1.h> using namespace std; PHYS_FIELD :: PHYS_FIELD(): G(N) { cout<< " from phys_field.cpp "<<endl; cout<<N<<endl; for (int i=0; i<N ; i++) cout<<i<<" "<<G(i)<<endl; };：

main.cpp

#include "dim.h" #include "phys_field.h" using namespace std; int main(int argc, char* argv[]){ PHYS_FIELD *F= new PHYS_FIELD(); return 0; }：

{{1}}

Answer 1

修改类arr1并添加一个接受零参数的构造函数（这样我们可以声明arr1 G，然后在DIM :: DIM构造函数中构建它

arr1()
{

}

类DIM：

protected:
    arr1<double> G;     //I've moved G from the constructor so that PHYS_FIELD can inherit it directly


DIM::DIM()
{
    N=10;
    G = arr1<double>(N);

    for (int i=0; i<N; i++)
        G(i)=i;

};

class PHYS_FIELD

从PHYS_FIELD标题中删除arr1<double> G;，以便它不会隐藏从DIM继承的G

PHYS_FIELD::PHYS_FIELD()   { //removed G(N)

    cout << " from phys_field.cpp " << endl;
    cout << N << endl;

    for (int i=0; i<N; i++)
        cout << i << " " << G(i) << endl;

};

这是你在找什么？

将数组传递给C ++中的派生类

1 个答案: