我有以下四个文件:
arrayListType.h
: 以模板方式声明和定义arrayListType
类。unorderedArrayListType.h
: 继承自arrayListType
类,并以模板方式声明和定义unorderedArrayListType
类。main1.cpp
: 测试程序,用于测试unorderedArrayListType
类。Makefile
当在 unorderedArrayListType
类中访问 arrayListType
的受保护变量时,出现编译错误,例如:"length not declared in this scope"、"list not declared in this scope",其中 length 和 list 是 arrayListType
类的受保护变量。
以下是代码:
arrayListType.h
#ifndef H_arrayListType
#define H_arrayListType
#include <iostream>
using namespace std;
template <class elemType>
class arrayListType
{
public:
const arrayListType<elemType>&operator=(const arrayListType<elemType>&);
bool isEmpty() const;
bool isFull() const;
int listSize() const;
int maxListSize() const;
void print() const;
bool isItemAtEqual(int location, const elemType& item) const;
virtual void insertAt(int location, const elemType& insertItem) = 0;
virtual void insertEnd(const elemType& insertItem) = 0;
void removeAt(int location);
void retrieveAt(int location, elemType& retItem) const;
virtual void replaceAt(int location, const elemType& repItem) = 0;
void clearList();
virtual int seqSearch(const elemType& searchItem) const;
virtual void remove(const elemType& removeItem) = 0;
arrayListType(int size = 100);
arrayListType(const arrayListType<elemType>& otherList);
virtual ~arrayListType();
protected:
elemType *list;
int length;
int maxSize;
};
template <class elemType>
bool arrayListType<elemType>::isEmpty() const
{
return (length == 0);
}
// remaining non-virtual functions of arrayListType class
#endif
无序数组列表类型.h
#ifndef H_unorderedArrayListType
#define H_unorderedArrayListType
//#include <iostream>
#include "arrayListType.h"
//using namespace std;
template <class elemType>
class unorderedArrayListType: public arrayListType<elemType>
{
public:
void insertAt(int location, const elemType& insertItem);
void insertEnd(const elemType& insertItem);
void replaceAt(int location, const elemType& repItem);
int seqSearch(const elemType& searchItem) const;
void remove(const elemType& removeItem);
unorderedArrayListType(int size = 100);
};
template <class elemType>
void unorderedArrayListType<elemType>::insertAt(int location, const elemType& insertItem)
{
for(int i = length; i > location; i--)
list[i] = list[i - 1];
list[location] = insertItem;
length++;
}
// Remaining virtual functions that need to be defined by the inherited class
#endif
主函数1.cpp
#include <iostream>
#include "unorderedArrayListType.h"
using namespace std;
int main()
{
unorderedArrayListType<int> intList(25);
int number;
cout<<"Line 3: Enter 8 integers: ";
for(int count = 0; count < 8; count++)
{
cin>>number;
intList.insertEnd(number);
}
cout<<"Line 8: intList: ";
intList.print();
cout<<endl;
}
Makefile:all: main1
main1.o: main1.cpp
g++ -c -Wall main1.cpp
main1: main1.o
g++ -Wall main1.o -o main
clean:
rm -f *.o *~ main1
以下是编译错误:make
g++ -c -Wall main1.cpp
In file included from main1.cpp:2:
unorderedArrayListType.h: In member function 'void unorderedArrayListType<elemType>::insertAt(int, const elemType&)':
unorderedArrayListType.h:30: error: 'length' was not declared in this scope
unorderedArrayListType.h:31: error: 'list' was not declared in this scope
unorderedArrayListType.h:33: error: 'list' was not declared in this scope
列出了unorderedArrayListType
的更多函数,并指示保护变量未在范围内声明。想知道可能的错误是什么。
新错误:
make
g++ -Wall main1.o -o main
Undefined first referenced
symbol in file
arrayListType<int>::seqSearch(int const&) constmain1.o
ld: fatal: Symbol referencing errors. No output written to main
collect2: ld returned 1 exit status
*** Error code 1
make: Fatal error: Command failed for target `main1'