我试过阅读这篇文章，但我并没有真正理解它：
What is an undefined reference/unresolved external symbol error and how do I fix it?
我直接从书中复制了这个程序，无法让它工作。我想在开始添加作业之前确保它有效。 有人可以告诉我为什么我会收到这些错误。
LNK2019 unresolved external symbol "public: void __thiscall
arrayListType<int>::print(void)const " (?print@?$arrayListType@H@@QBEXXZ)
referenced in function _main
LNK2019 unresolved external symbol "public: void __thiscall
arrayListType<int>::insertAt(int,int const &)" (?insertAt@?
$arrayListType@H@@QAEXHABH@Z) referenced in function _main
LNK2019 unresolved external symbol "public: void __thiscall
arrayListType<int>::remove(int const &)" (?remove@?
$arrayListType@H@@QAEXABH@Z) referenced in function _main
main.cpp中：
#include <iostream>
#include <string>
#include "arrayListType.h"
using namespace std;
int main() {
arrayListType<int> intList(100);
arrayListType<string> stringList;
int number;
cout << "List 10: Enter 5 integers: ";
for (int counter = 0; counter < 5; counter++) {
cin >> number;
intList.insertAt(counter, number);
}
cout << endl;
cout << "List 19: The list you entered is: ";
intList.print();
cout << endl;
cout << "List 20: Enter the item to be deleted: ";
cin >> number;
intList.remove(number);
cout << "Line 23: After removing " << number << ", the list is" << endl;
intList.print();
cout << endl;
string str;
cout << "Line 27: Enter 5 strings: ";
for (int counter = 0; counter < 5; counter++) {
cin >> str;
stringList.insertAt(counter, str);
}
cout << endl;
cout << "Line 34: The list you enterd is: " << endl;
stringList.print();
cout << endl;
cout << endl;
cout << "Line 37: Enter the string you want to be deleted: " << endl;
cin >> str;
stringList.remove(str);
cout << "Line 40: After removing " << str << ", the list is: " << endl;
stringList.print();
cout << endl;
return 0;
}
arrayListType.h：
#pragma once
#ifndef ARRAY_LIST_TYPE_H
#define ARRAY_LIST_TYPE_H
template <class elemType>
class arrayListType {
public:
const arrayListType<elemType>& operator = (const arrayListType<elemType>&);
bool isEmpty() const;
bool isFull() const;
int listSize() const;
int masListSize() const;
void print() const;
bool isItemEqual(int location, const elemType& item) const;
void insertAt(int location, const elemType& insertItem);
void insertEnd(const elemType& insertItem);
void retrieveAt(int location, elemType& retItem) const;
void removeAt(int location);
void replaceAt(int location, const elemType& repItem);
void clearList();
int seqSearch(const elemType& item) const;
void insert(const elemType& insertItem);
void remove(const elemType& removeItem);
arrayListType(int size = 100);
arrayListType(const arrayListType<elemType>& otherList);
~arrayListType();
int min();
protected:
elemType *list;
int length;
int maxSize;
};
#endif
arrayListType.cpp：
//implementation file
//arrayListType.cpp
#include "arrayListType.h"
//copy constructor
template <class elemType>
arrayListType<elemType>::arrayListType(const arrayListType<elemType>& otherList) {
maxSize = otherList.maxSize;
length = otherList.length;
list = new elemType[maxSize];
asser(list != null);
for (int j = 0; j < length; j++) {
list[j] = otherList.list[j];
}
}
//overloading the assignmnet operator
template <class elemType>
const arrayListType<elemType>& arrayListType<elemType>::operator=(const arrayListType<elemType>& otherList) {
if (this != &otherList) {
delete[] list;
maxSize = otherList.maxSize;
length = otherList.length;
list = new elemType[maxSize];
assert(list != NULL);
for (int i = 0; i < length; i++) {
list[i] = otherList.list[i];
}
}
return *this;
}
template <class elemType>
bool arrayListType<elemType>::isEmpty() const {
return (length == 0);
}
template <class elemType>
bool arrayListType<elemType>::isFull() const {
return (length == maxSize);
}
template <class elemType>
int arrayListType<elemType>::listSize() const {
return length;
}
template <class elemType>
int arrayListType<elemType>::masListSize() const {
return maxSize;
}
template <class elemType>
void arrayListType<elemType>::print() const {
for (int i = 0; i < length; i++) {
cout << list[i] << " ";
}
cout << endl;
}
template <class elemType>
bool arrayListType<elemType>::isItemEqual(int location, const elemType& item) const {
return(list[location] == item);
}
template <class elemType>
void arrayListType<elemType>::insertAt(int location, const elemType& insertItem) {
if (location < 0 || location >= maxSize) {
cerr << "The position of the item to be inserted is out of range." << endl;
}
else
if (length >= maxSize) {
cerr << "Cannot insert in a full list" << endl;
}
else {
for (int i = length; i > location; i--) {
list[i] = list[i - 1];
}
list[location] = insertItem;
length++;
}
}
template <class elemType>
void arrayListType<elemType>::insertEnd(const elemType& insertItem) {
if (length >= maxSize) {
cerr << "Cannot insert in a full list." << endl;
}
else {
list[length] = insertItem;
length++;
}
}
template <class elemType>
void arrayListType<elemType>::removeAt(int location) {
if (location < 0 || location >= length) {
cerr << "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--;
}
}
}
template <class elemType>
void arrayListType<elemType>::retrieveAt(int location, elemType& retItem) const {
if (location < 0 || location >= length) {
cerr << "The location of the item to be retrieved is out of range." << endl;
}
else {
retItem = list[location];
}
}
template <class elemType>
void arrayListType<elemType>::replaceAt(int location, const elemType& repItem) {
if (locatoin < 0 || location >= length){
cerr << "The location of the item to be replaced is out of range." << endl;
}
else {
list[location] = repItem;
}
}
template <class elemType>
void arrayListType<elemType>::clearList() {
length = 0;
}
template <class elemType>
int arrayListType<elemType>::seqSearch(const elemType& item) const {
int loc;
bool found = false;
for (loc = 0; loc < length; loc++) {
if (list[loc] == item) {
found = true;
break;
}
if (found) {
return loc;
}
else {
return -1;
}
}
}
template <class elemType>
void arrayListType<elemType>::insert(const elemType& insertItem) {
int loc;
if (length == 0) {
list[length++] = insertItem;
}
else if (length == maxSize) {
cerr << "Cannot inser in a full list." << endl;
}
else {
loc = seqSearch(insertItem);
if (loc == -1) {
list[length++] = insertItem;
}
else {
cerr << "The item to be inserted is already in the list. "
<< "No duplicates are allowed." << endl;
}
}
}
template <class elemType>
void arrayListType<elemType>::remove(const elemType& removeItem) {
int loc;
if (length == 0) {
cerr << "Cannot delete from an empty list." << endl;
}
else {
loc = seqSearch(removeItem);
if (loc != -1) {
removeAt(loc);
}
else {
cerr << "The item to be deleted is not in the list." << endl;
}
}
}
template <class elemType>
arrayListType<elemType>::arrayListType(int size) {
if (size < 0) {
cerr << "The array size must be positive. Creating an array of size 100." << endl;
maxSize = 100;
}
else {
maxSize = size;
}
length = 0;
list = new elemType[maxSize];
assert(list != NULL);
}
//template <class elemType>
//arrayListType<elemType>::arrayListType(const arrayListType<elemType>& otherList) {
//
//}
template <class elemType>
arrayListType<elemType>::~arrayListType() {
delete[] list;
}
template <class elemType>
int arrayListType<elemType>::min() {
}