無法計數作爲輸入的位數

Question

我的程序：從用戶那裏獲得有關個人詳細信息的輸入信息，然後輸出信息。

我的問題：程序無法計算作爲電話號碼字段輸入的位數。它接受超過10位數字作爲電話號碼的輸入。

我的目標：檢查「電話號碼」的輸入並確保該號碼是10位數字。

我的代碼：

#include <iostream> 
#include <string> 
#include <limits> 

using namespace std; 

class Personal_Details 
{ 
public: 
    void setFirstName (string newFirstName); 
    void setLastName (string newLastName); 
    void setBirthdate (int newBirthday); 
    void setEMail  (string newEMail); 
    void setPhoneNumber (int newPhoneNumber); 
    void QUESTIONS(); 
    string getFirstName(); 
    string getLastName(); 
    string getEMail(); 
    int getPhoneNumber(); 
    int getBirthdate(); 

private: 
    string FirstName; 
    string LastName; 
    string EMail; 
    int PhoneNumber; 
    int Birthdate; 
}; 

void Personal_Details :: setFirstName (string newFirstName) 
{ 
    FirstName = newFirstName; 
} 

void Personal_Details :: setLastName (string newLastName) 
{ 
    LastName = newLastName; 
} 

void Personal_Details :: setBirthdate (int newBirthdate) 
{ 
    Birthdate = newBirthdate; 
} 

void Personal_Details :: setEMail (string newEMail) 
{ 
    EMail = newEMail; 
} 

void Personal_Details :: setPhoneNumber (int newPhoneNumber) 
{ 
    PhoneNumber = newPhoneNumber; 
} 

string Personal_Details :: getFirstName() 
{ 
    return FirstName; 
} 

string Personal_Details :: getLastName() 
{ 
    return LastName; 
} 

int Personal_Details :: getBirthdate() 
{ 
    return Birthdate; 
} 

string Personal_Details :: getEMail() 
{ 
    return EMail; 
} 

int Personal_Details :: getPhoneNumber() 
{ 
    if (PhoneNumber>12) 
    { 
     cout <<"INVALID. Program will now close."; 
    } 
    system ("PAUSE"); 

    return PhoneNumber; 
} 

void Personal_Details :: QUESTIONS() 
{ 
    cout << "A.) Enter the following details:-" << endl <<endl; 
    cout << "First Name: "; 
    getline (cin, FirstName); 
    cout << endl; 

    cout << "Last (Family) Name: "; 
    getline (cin, LastName); 
    cout << endl; 

    cout << "Birthdate: "; 
    cin >> Birthdate; 
    std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); 
    cout << endl; 

    cout << "Email Address: "; 
    getline (cin, EMail); 
    cout << endl; 

    cout << "Phone Number: "; 
    cin >> PhoneNumber; 
    cout << endl; 

    cout<< FirstName <<" "<< LastName << endl 
     <<"Birthdate: "<< Birthdate << endl 
     <<"Email ID: "<< EMail << endl 
     <<"Phone Number: "<< PhoneNumber << endl; 
} 

int main() 
{ 
    Personal_Details NewContact; 
    cout << "- Add New Contact Information -" << endl << endl; 
    cout << "Note: Please type in only intergers (numbers) for 'Birthdate' and 'Phone Number' field. Also, phone number should be less than/or equal to 10 digits." << endl; 
    cout << "Else, this program will terminate abruptly." << endl << endl; 
    NewContact.QUESTIONS(); 
    cout << endl << endl; 

    cout << "Press Any Key to Exit."; 
    cin.ignore(); 
    cin.get(); 

    return 0; 
} 

請您可以查看和檢查爲什麼我不能輸入一個真正的10位數字的電話號碼？我是C++的新手，所以我無法找出解決方案。謝謝你的幫助！

Answer 1

您將電話號碼存儲爲int，但整數範圍是-2,147,483,648至2,147,483,647;在該範圍外輸入一個10位數字會導致溢出，並可能導致程序崩潰。

您可能希望以電話號碼的形式讀入字符串，檢查每個字符的有效性，然後根據需要對其進行處理（例如：區號的變量，7位數的變量，拒絕超出範圍輸入並重新提示）。