-3
これはリンクされたリストプログラムの割り当てのためのものです。私は、メインの方法でこれらの行に4つのエラーを取得し続けます。私は誰が私にスコープに何が間違っているか教えてくれるのだろうかと思っていました。"範囲外でデケールされていません"というエラーが表示される
error: ‘addFirst’ was not declared in this scope addFirst(booklist);
error: ‘addLast’ was not declared in this scope addLast(booklist);
error: ‘isInTheList’ was not declared in this scope isInTheList(booklist);
error: ‘deleteBook’ was not declared in this scope deleteBook(booklist);
#include <iostream>
#include <string>
#include "Program3.h"
#include <limits> // for numeric limits
using namespace std;
//Implementation for class BookList START
void BookList::addFirst(BookNode * book){ //To add a new head node
book -> setNext(head);
head = book;
}
void BookList::addLast(BookNode * book){ //To add a new node at the end
if(!head){
addFirst(book);
}
else{
BookNode * temp = head;
while(temp->getNext() != NULL){
temp = temp->getNext();
}
temp -> setNext(book);
}
}
void BookList::traverse(){ //TO go through the whole linked list
BookNode * temp = head;
while(temp != NULL){
std::cout << temp -> getTitle()<<std::endl;
temp = temp -> getNext();
}
}
bool BookList::isInTheList(std::string title){ //To check the linked list for a specific title
BookNode * temp = head;
while(temp != NULL){
if(temp -> getTitle() == title){
return true;
}
temp = temp -> getNext();
}
return false;
}
bool BookList::deleteBook(std::string title){ //to delete a book/title
if(head == NULL){ // or if(!head) To check if the linked list is empty
return false;
}
BookNode * prev = NULL;
BookNode * cur = head;
if(cur -> getTitle() == title){ //Checking if the title is the first node
head = head -> getNext();
delete cur;
return true;
}
while(cur != NULL && cur -> getTitle() != title){ //Checking through the linked list for the title
prev = cur; //The while loop will stop when it has gone though the whole linked list or if it matches with the title
cur = cur -> getNext();
}
if(cur == NULL){ //There is no matching entry
return false;
}
else{
prev -> setNext(cur -> getNext());
delete cur;
return true;
}
}
BookList::~BookList(){
while(head != NULL){
string tempTitle = head->getTitle();
deleteBook(tempTitle);
cout << "Book " << tempTitle << "has been deleted" <<endl;
}
}
int getUserChoice(){
int choice = 0;
cout << "Welcome to the e-library, please make a choice from the menu below" << endl;
cout << "1. Add a book at the beginning" << endl;
cout << "2. Add a book at the end" << endl;
cout << "3. Find a book in the list" << endl;
cout << "4. Delete a book in the list" << endl;
cout << "5. Print all the books in the list" << endl;
cout << "6. Exit " << endl;
if(cin >> choice){ //confirming that cin succeeded
if(choice > 0 && choice < 7){
cin.ignore(); //dump newline character
return choice;
}
else{
cin.ignore();//dump newline character
return 0;
}
}
else{
cin.clear(); //bring cin back from failed status
cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
return 0;
}
}
int main(){
BookList booklist; //Create an object of ArrayList
int choice = getUserChoice(); //Prompting user for an input
while (choice != 6){
switch(choice){
case 0:
cout << "Invalid choice. Please Choose between 1 and 6." <<endl; // 0 is not a given choice, loop reruns
break;
case 1:
addFirst(booklist);
break;
case 2:
addLast(booklist);
break;
case 3:
isInTheList(booklist);
break;
case 4:
deleteBook(booklist);
break;
case 5:
booklist.traverse();
break;
default:
break;
}
choice = getUserChoice(); // prompt user to enter the choice again
return 0;
}
}
、その後、私のヘッダファイルが同じフォルダにProgram.hとして保存され、コードが
#ifndef PGM_03_H//<-
#define PGM_03_H//<- both these need to have the same name
#include <string>
using namespace std;
/*class definition for BookNode
* which is non-compatible. i.e it has a pointer to the next BookNode
*/
class BookNode{
private :
std::string bookTitle;
BookNode * next;
public :
//default constructor
BookNode(){bookTitle = "";next = NULL;}
//custom constructor
//it initializes book with title
BookNode(string title){
bookTitle = title;
next = NULL;
}
//getter functions
std::string getTitle(){
return bookTitle;
}
BookNode * getNext(){
return next;
}
//setter functions
void setTitle(std::string newTitle){
bookTitle = newTitle;
}
void setNext(BookNode * newNext){
next = newNext;
}
};
/*
* class definition for BookList
* which is a linked list that uses object of BookNode as node.
* it has only one variable: head, which is a BookNode pointer.
*/
class BookList{
private:
BookNode * head;
public:
//default constructor
BookList(){
head = NULL;
}
//destructor, which will be called automatically
//it deletes all nodes in the linkedlist
~BookList();
//add new node as the first node in the booklist
void addFirst(BookNode *);
//add new node as the last node in the booklist
void addLast(BookNode *);
//traverse function. It will print out info on BookNode
void traverse();
//check if the given book is in the list
bool isInTheList(std::string);
//delete the given book
//return true if it was deleted
//return false if it was not found
bool deleteBook(std::string);
};
#endif
デケールではないと宣言する必要があります。 – Hasi
あなたの質問を編集するには、あなたの質問を編集することができます。それはまた、すべてのコードを[mcve]に置き換える良い機会になります。 –