我正在为密码验证器编写类程序。我需要密码至少为6个字符，但我也将密码限制为最多10个（不是必需的，但希望如此）。
该程序运行良好，其他验证也有效，直到尝试添加超过10个字符的密码为止。我可以浏览并重新输入一个新密码，然后我收到一条消息，提示它现在是有效密码。但随后出现以下错误：
运行时检查失败＃2-变量'password'周围的堆栈已损坏。
如果设置宽度，我可以解决该错误，但是我知道这不是正确的处理方式。另外，我认为通过设置宽度，用户将无法输入该大小以外的任何内容。
这是我的代码：
#include <iostream>
#include <iomanip>
#include <cstring>
#include <cctype>
using namespace std;
//Function prototypes
bool validatePassword(char *); //function to test pw requirements
bool validateUppercase(char *); //function to test for upper case value
bool validateLowercase(char *); //function to test for lowercase value
bool validateNumber(char *); //function to test for a number value
bool validateLength(char *); //function to test for password length
int main()
{
//Variabes
char password[11]; //set the maximum number of char for password include the end delimiter
int size; //size of the array
//Prompt user to enter a password based on criteria
cout << "Please enter a password that meets the following criteria: \n";
cout << "1. A minimum of 6 characters up to a max of 10. \n";
cout << "2. Contains atleast one uppercase and one lowercase character. \n";
cout << "3. Contains atleast one number. \n\n";
//cout << "****Please note if you have more the 10 characters \n";
//cout << " the program will only accept the first 10***\n";
cout << "\nPlease enter your password: ";
cin >> password;
//cin >> setw(10) >> password; //set this so I would not get a runtime error
size = strlen(password); //determines the length of the password
do
{
while (!validatePassword(password)) //if the functions returns a false value
{
cout << "\nYour password does not meet the requirements. ";
cout << "\nEnter a new password: ";
cin >> password;
size = strlen(password);
}
} while (size > 10);
if (validatePassword(password))
{
cout << "\nYour password " << password << " meets the requirements. \n"; //if the function returns a true value
}
system ("pause");
return 0;
}
//This function calls the other validation functions
bool validatePassword(char *pass)
{
int size = strlen(pass);
return (validateLength(pass) && validateUppercase(pass) && validateLowercase(pass) && validateNumber(pass) == true);
}
//This function validates the length of the password
bool validateLength (char *pass)
{
int size = strlen(pass);
if (size >= 6 && size < 10)
return true;
else
{
cout << "\n\nThe password you entered either contained to little or to many characters.";
cout << "\nA minimum of 6 characters to a maximum of 10 is required.";
return false;
}
}
//This function checks to see if the password contains an uppercase char
bool validateUppercase(char *pass)
{
int size = strlen(pass);
for (int count = 0; count < size; count++)
{
if (isupper(pass[count]))
return true;
}
cout << "\n\nThe password must contain at least one uppercase character. ";
return false;
}
//This function checks to see if the password contains an lowercase char
bool validateLowercase(char *pass)
{
int size = strlen(pass);
for (int count = 0; count < size; count++)
{
if (islower(pass[count]))
return true;
}
cout << "\n\nThe password must contain at least one lowercase character. ";
return false;
}
//This function checks to see if the password contains an number char
bool validateNumber(char *pass)
{
int size = strlen(pass);
for (int count = 0; count < size; count++)
{
if (isdigit(pass[count]))
return true;
}
cout << "\n\nThe password must contain at least one number. " ;
return false;
}
最佳答案
使用cstrings时，如果有足够的空间，运算符<<将读取一个字符串并在缓冲区的末尾自动添加空字节字符。
您将缓冲区分配为11，因此当输入的密码大于10时，将不存在终止字符串的空字节，从而导致strlen等问题。实际上，strlen所做的只是读取输入并递增计数器，直到遇到\0。
您现在有两个选择：
继续使用cstring并增加缓冲区的大小（足够大以避免发生意外），
切换到c ++的string类，该类是可以动态增加的char数组（强烈建议here is a link to get started）。
另外，关于代码：您有很多不必要的东西。例如：
do
{
while (!validatePassword(password)) //if the functions returns a false value
{
cout << "\nYour password does not meet the requirements. ";
cout << "\nEnter a new password: ";
cin >> password;
size = strlen(password);
}
} while (size > 10);
if (validatePassword(password))
{
cout << "\nYour password " << password << " meets the requirements. \n"; //if the function returns a true value
}
可以替换为：
while (!validatePassword(password))
{
cout << "\nYour password does not meet the requirements. ";
cout << "\nEnter a new password: ";
cin >> password;
}
cout << "\nYour password " << password << " meets the requirements. \n";
validatePassword调用validateLength来检查strlen(pass) <= 10，并且只有在密码正确时才能退出第一个循环。另一个改进是将密码的大小传递给函数，以避免在任何地方调用
strlen（在C语言中，总是使用char *参数传递该大小是很常见的）。关于c++ - 堆栈溢出运行时错误C++，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/41796006/