我不能让我的删除功能从列表中删除项目

Question

当我添加一个人它会被正确添加，但是当我去删除它的名称说没有找到该名称。该程序允许用户在电话簿中创建的电话簿和编辑信息对上述程序

#include <iostream> 
#include <string> 
#include "PhoneBook.h" 
using namespace std; 
char MenuSelection(); 

int main() { 
    char Selection; 
    PhoneBook myList; 
    do{ 
     Selection = MenuSelection(); 
     switch (Selection){ 
      case 'a': 
       myList.AddEntry(); 
       break; 
      case 'd': 
       myList.DisplayNamesAndNumbers(); 
       break; 
      case 's': 
       myList.FindEntry(); 
       break; 
      case 'r': 
       myList.DeleteFunction(); 
       break; 
      case 'q': 

       break; 
      default : 
       cout << "\n\nNot a command choice\n"; 
       cout << "Press enter to continue"; 
       cin.get(); 
       cin.get(); 
       system ("clear"); 
     } 
    }while (Selection != 'q'); 
    myList.MakeFile(); 
    cout << "Press enter to continue"; 
    return 0; 
} 

//This function prints out the opening menu and allws users to enter a command. 
char MenuSelection(){ 
    char Response; 
    cout << "\n     MENU\n"; 
    cout << "a - add a name and phone number\n"; 
    cout << "d - display names and phone number\n"; 
    cout << "r - remove a name and phone number\n"; 
    cout << "s - search for a name and return the phone number\n"; 
    cout << "q - quit program\n\n"; 
    cout << "Enter your choice: "; 
    cin >> Response; 
    return Response; 
} 

头文件这是类，其允许用户操纵的电话簿。

#include <iostream> 
#include <fstream> 
#include <string> 
using namespace std; 
const int GROUPSIZE = 100; 
struct contact {string NameEntry; string PhoneNumber;}; 

class PhoneBook { 
private: 
    int Size; 
    contact ContactNumber [GROUPSIZE]; 
public: 
    PhoneBook(); 
    void MakeFile(); 
    void AddEntry(); 
    void FindEntry(); 
    string DisplayNamesAndNumbers(); 
    string DeleteFunction(); 
}; 

//opens the file and adds names and numbers to the text file 
PhoneBook::PhoneBook(){ 
    string PersonsName, PhoneNum; 
    int i = 0; 
    ifstream infile; 
    infile.open ("phonebook.txt"); 
    if (!infile){ 
     cout << "File does not exist"; 
    } 
    else{ 
     while (!infile.eof()){ 
      infile >> PersonsName >> PhoneNum; 
      ContactNumber [i].NameEntry = PersonsName; 
      ContactNumber [i++].PhoneNumber = PhoneNum; 
     } 
     Size = i; 
     infile.close(); 
    } 
} 

//adds name and phone number to the list 
void PhoneBook::AddEntry(){ 
    string PersonsName, PhoneNum; 
    cout << "\n\nEnter the name to be added: "; 
    cin >> PersonsName; 
    cout << "Enter the phone number for " << PersonsName << ": "; 
    cin >> PhoneNum; 
    ContactNumber [Size].NameEntry = PersonsName; 
    ContactNumber [Size].PhoneNumber = PhoneNum; 
    Size++; 
    cout << "Press enter to continue"; 
    cin.get(); 
    cin.get(); 
    system ("clear"); 
} 

//finds names and numbers in the list 
void PhoneBook::FindEntry(){ 
    int Location, Counter; 
    string Contact; 
    cout << "\n\nName to find: "; 
    cin >> Contact; 
    Counter = 0; 
    while (Counter < Size){ 
     Counter++; 
    //for (int i = 0; i < size; i++){ 
     if (strcmp(Contact.c_str(),ContactNumber [Counter].NameEntry.c_str())) 
      Location = Counter; 
     else 
      Location = -1; 
    } 
    if (Location != -1) 
     cout << "The phone number for " << Contact << " is " << ContactNumber [Location].PhoneNumber << endl; 
    else 
     cout << Contact << " not in phonebook\n"; 
    cout << "Press enter to continue"; 
    cin.get(); 
    cin.get(); 
    system ("clear"); 
} 

//displays all information in the list 
string PhoneBook::DisplayNamesAndNumbers(){ 
    string PersonsName, PhoneNum; 
    int Check = 1; 
    cout << "\n\nList is being sorted\n"; 
    while (Check == 1){ 
     cout << "Name\t\tTelephone Number"; 
     for (int i = 0; i < Size; i++){ 
      cout << ContactNumber[i].NameEntry << "\t\t" << ContactNumber[i].PhoneNumber << "\n"; 
     } 
     break; 
    } 
    cout << "Press enter to continue"; 
    cin.get(); 
    cin.get(); 
    system("clear"); 
    return ""; 
} 

//deletes information from the list 
string PhoneBook::DeleteFunction(){ 
    char Answer; 
    string PersonsName; 
    int Location; 
    cout << "\n\nName to remove: "; 
    cin >> PersonsName; 
    for (int i = 0; i < GROUPSIZE; i++){ 
     if (!strcmp(PersonsName.c_str(),ContactNumber[i].NameEntry.c_str())) 
      Location = i; 
     else 
      Location = -1; 
    } 
    if (Location != -1){ 
     ContactNumber[Location].NameEntry = ContactNumber[Size].NameEntry; 
     ContactNumber[Location].PhoneNumber = ContactNumber[Size].PhoneNumber; 
     cout << PersonsName <<" removed from phonebook\n"; 
     cout << "Press enter to continue"; 
     cin.get(); 
     cin.get(); 
     system("clear"); 
     return""; 
    } 
    cout << "Name not found in phonebook\n"; 
    cout << "Press enter to continue"; 
    cin.get(); 
    cin.get(); 
    system ("clear"); 
    return""; 
} 

//closes the file at the end of the program 
void PhoneBook::MakeFile(){ 
    ofstream outfile; 
    outfile.open("phonebook.txt"); 
    for (int i = 0; i < GROUPSIZE; i++){ 
     outfile << ContactNumber[i].NameEntry << " " << ContactNumber[i].PhoneNumber<<"\n"; 
    } 
    outfile.close(); 
} 

Answer 1

看起来你忘了在找到匹配项后删除你的删除。

Answer 2

我认为你使用的是strcmp错误。如果两个字符串匹配，它将返回0，因此您需要strcmp() == 0。看看here为可能的返回值。
接下来，因为你已经在使用std::string S，只需直接比较这些，他们支持：

if(Contact == ContactNumber[Counter].NameEntry) 

此外，你还没有找到入口后，破坏你的for循环的出要删除。

---

另一个侧面提醒：您的电话簿可以包含重复的条目，因为你不检查，如果这个人在你AddEntry功能已经exsists。
最后，在经历了所有这些基本上从一个字符串映射到另一个字符串的痛苦之后，为了进一步使用这样的数据结构，请考虑使用std::map。 :)

#include <map> 

int main(){ 
    map<string /*name*/, string /*number*/> phonebook; 
    phonebook["Meyers"] = "03024233"; 
    string number = phonebook.find("Meyers"); 
} 

Answer 3

contact ContactNumber [GROUPSIZE]; 

当前实现，我认为它不会删除对象的数组中的条目。你有GROUPSIZE号码的contact对象（即一组对象）。数组无法修改大小。如果你需要从数组中删除一个元素，首先你需要一个contact类型的引用。

contact *ContactNumber ; // new it with GROUPSIZE number of objects in PhoneBook constructor. 

如果您需要在m位置删除元素，你需要使用复制交换规则GROUPSIZE - m翻译。即m+1位置对象应该位于m位置，m+2位置对象应位于m+1位置，....是我认为正确的执行方式。并且请记住在PhoneBook的析构函数中使用delete[] ContactNumber;以避免内存泄漏。

为了避免所有的痛苦，改用std::vector代替。