问题
My question has changed from the other one I have posted. I started out with multiple files and decided to put it all in one main.cpp file for now just to get it working.
main.cpp:
#include <iostream>
using namespace std;
class arrayListType {
public:
bool isEmpty() ;
bool isFull() ;
int listSize() ;
int maxListSize() ;
void print() ;
bool isItemAtEqual(int location, int item) ;
virtual void insertAt(int location, int insertItem) = 0;
virtual void insertEnd(int insertItem) = 0;
void removeAt(int location);
void retrieveAt(int location, int& retItem) ;
virtual void replaceAt(int location, int repItem) = 0;
void clearList();
virtual int seqSearch(int searchItem) const = 0;
virtual void remove(int removeItem) = 0;
arrayListType (int size = 100);
arrayListType ( arrayListType& otherList);
virtual ~arrayListType();
protected:
int *list;
int length;
int maxSize;
};
bool arrayListType::isEmpty() {
return (length == 0);
}
bool arrayListType::isFull() {
return (length == maxSize);
}
int arrayListType::listSize() {
return length;
}
int arrayListType::maxListSize() {
return maxSize;
}
void arrayListType::print() {
for (int i = 0; i < length; i++)
cout << list[i] << " ";
cout << endl;
}
bool arrayListType::isItemAtEqual(int location, int item) {
if (location < 0 || location >= length) {
cout << "The location of the item to be compared is out range." << endl;
return false;
}
else
return(list[location] == item);
}
void arrayListType::removeAt(int location) {
if (location < 0 || location >= length){
cout << "The location of the item to be removed is out of range." << endl;
}
else {
for (int i = location; i < length -1; i++)
list[i] = list[i+1];
length--;
}
}
void arrayListType::retrieveAt(int location, int& retItem) {
if (location < 0 || location >= length) {
cout << "The location of the item to be retrieved is out of range." << endl;
}
else
retItem = list[location];
}
void arrayListType::clearList() {
length = 0;
}
arrayListType::arrayListType (int size) {
if (size <= 0) {
cout << "The array size must be positive. Creating an array of the size 100." << endl;
maxSize = 100;
}
else
maxSize = size;
length = 0;
list = new int[maxSize];
}
class orderedArrayListType: public arrayListType {
public:
void insertAt(int location, int insertItem);
void insertEnd(int insertItem);
void replaceAt(int location, int repItem);
int seqSearch(int searchItem) const;
void insert (int insertItem);
void remove (int removeItem);
orderedArrayListType (int size = 100);
~orderedArrayListType();
private:
void quickSort();
};
void orderedArrayListType::quickSort(){
//private function for sorting "list."
//using a "quicksort" method
//addapted from: http://www.algolist.net/Algorithms/Sorting/Quicksort
if (length == 0) {
cout << "Cannot sort an ampty list." << endl;
}
else {
int left = 0, right = length;
int i = left, j = right;
int tmp;
int pivot = list[(left + right) / 2];
/* partition */
while (i <= j) {
while (list[i] < pivot)
i++;
while (list[j] > pivot)
j--;
if (i <= j) {
tmp = list[i];
list[i] = list[j];
list[j] = tmp;
i++;
j--;
}
};
/* recursion */
if (left < j)
quickSort();
if (i < right)
quickSort();
}
}
void orderedArrayListType::insertAt(int location, int insertItem){
if (location < 0 || location >= length){
cout << "The location of the item to be removed "
<< "is out of range." << endl;
}
else if(length == maxSize){
cout << "Cannot insert in a full list." << endl;
}
else {
for (int j = length; j < location; j--){
list[j+1] = list[j];
/*
Start at the end of the array and move each item
out by one. Coninue until list[j] is at the
location, then set the list[location] to the value.
*/
}
list[location] = insertItem;
length++;
}
quickSort();
}
void orderedArrayListType::insertEnd(int insertItem) {
if (length == maxSize){
cout << "Cannot insert in a full list." << endl;
}
else {
list[length] = insertItem;
length++;
}
quickSort();
}
void orderedArrayListType::replaceAt(int location, int repItem) {
if (location < 0 || location >= length){
cout << "The location of the item to be replaced "
<< "is out of range." << endl;
}
else
list[location] = repItem;
quickSort();
}
int orderedArrayListType::seqSearch(int searchItem) const {
int loc;
bool found = false;
loc = 0;
while (loc < length && !found) {
if (list[loc] == searchItem)
found = true;
else
loc++;
}
if (found)
return loc;
else
return -1;
}
void orderedArrayListType::insert (int insertItem){
if (length == 0){
list[length++] = insertItem;
}
else if (length == maxSize){
cout << "Cannot insert in a full list." << endl;
}
else {
int loc;
bool found = false;
for (loc= 0; loc < length; loc++){
if (list[loc] >= insertItem){
found = true;
break;
}
}
for (int i = length; i > loc; i--) {
list[i] = list[i-1];
}
list[loc] = insertItem;
length++;
}
quickSort();
}
void orderedArrayListType::remove (int removeItem) {
int loc;
if (length == 0)
cout << "Cannot Delete from an ampty list." << endl;
else {
loc = seqSearch(removeItem);
if (loc != -1)
removeAt(loc);
else
cout << "The item to be deleted is not in the list." << endl;
}
}
orderedArrayListType::orderedArrayListType (int size)
:arrayListType(size){
}
int main() {
// orderedArrayList intlist(25);
// orderedArrayListType intList = new orderedArrayListType(25);
}
The exact error message:
/tmp/ccdTFaE0.o: In function
arrayListType::arrayListType(int)': main3.cpp:(.text+0x25c): undefined reference tovtable for arrayListType' /tmp/ccdTFaE0.o:(.rodata._ZTV20orderedArrayListType[vtable for orderedArrayListType]+0
x38): undefined reference toorderedArrayListType::~orderedArrayListType()' /tmp/ccdTFaE0.o:(.rodata._ZTV20orderedArrayListType[vtable for orderedArrayListType]+0orderedArrayListType::~orderedArrayListType()' /tmp/ccdTFaE0.o:(.rodata._ZTI20orderedArrayListType[typeinfo for orderedArrayListType]
x40): undefined reference to
+0x10): undefined reference to `typeinfo for arrayListType' collect2: ld returned 1 exit status
tldr;
#include <iostream>
using namespace std;
class arrayListType {
public:
bool isEmpty() const;
...
arrayListType (int size = 100);
arrayListType ( arrayListType& otherList);
virtual ~arrayListType();
protected:
int *list;
int length;
int maxSize;
};
//definitions
bool arrayListType::isEmpty() {
return (length == 0);
}
class orderedArrayListType: public arrayListType {
public:
void insertAt(int location, int insertItem);
...
orderedArrayListType (int size = 100);
~orderedArrayListType();
private:
void quickSort();
};
void orderedArrayListType::quickSort(){
...
}
void orderedArrayListType::insertAt(int location, int insertItem){
....
quickSort();
}
orderedArrayListType::orderedArrayListType (int size)
:arrayListType(size){
}
int main() {
orderedArrayList intlist(25);
// orderedArrayListType intList = new orderedArrayListType(25);
}
回答1:
What compiler are you using? Visual Studio 2010 gives this more helpful output:
1>cachesize.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall arrayListType::~arrayListType(void)" (??1arrayListType@@UAE@XZ) referenced in function "public: virtual void * __thiscall arrayListType::`scalar deleting destructor'(unsigned int)" (??_GarrayListType@@UAEPAXI@Z)
1>cachesize.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall orderedArrayListType::~orderedArrayListType(void)" (??1orderedArrayListType@@UAE@XZ) referenced in function "public: virtual void * __thiscall orderedArrayListType::`scalar deleting destructor'(unsigned int)" (??_GorderedArrayListType@@UAEPAXI@Z) 1>C:\Users\james\Documents\Visual Studio 2010\Projects\cachesize\Debug\cachesize.exe : fatal error LNK1120: 2 unresolved externals
You need to add bodies to virtual ~arrayListType(); and ~orderedArrayListType();.
You've declared them but not defined them. It compiles then!
回答2:
You're missing the destructor definitions:
arrayListType::~arrayListType() { }
orderedArrayListType::~orderedArrayListType() { }
Linker errors are usually not very useful. But this exact error is usually generated when you declare, but don't define, your destructor.
来源：https://stackoverflow.com/questions/12327679/c-undefined-reference-to-vtable