Question

我最近开始在线学习c ++并开始研究这段代码，但需要一些帮助来解决编译器给我带来的错误。基本上我只是想从用户那里获得一个密码，如果它是第一次使用'flag'变量并将加密形式的密码写入文本文件。如果用户第一次没有登录并且保存了密码，则读取加密文本，对其进行解密，并检查它是否等于用户输入的密码。

#include<iostream>
#include<string.h>
#include<fstream>
using namespace std;
char encryptpass(char *pass) //function to encrypt 
 {

   for( int i=0; pass[i] != '\0'; ++i )
   char enpass[10]= ++pass[i];
   return(enpass);


}
 char decryptpass(char *str)  // function to decrypt
{
for( ; str!='\0'; ++str )
char depass[10]= --str;
return(depass);

}

 int main()             // main function
{
int flag=0;
if(flag=0)
{
    cout<<"enter your password";
    char pass[10];
    cin>>pass;
    fstream file("userpass.txt",ios::in | ios::out);
    file<<enpass[10];
}
else
{
  cout<<"enter password";
  cin>>pass;
   bool check=false;
   static char str[10];
   file.seekg(ios::beg);
   file >> str;
   file.close();
   decryptpass(str);

     if(pass=depass)   // decrypted password is equal to input password ?
   {
       check=true;      // set boolen value to true
   }
 else
 {
   cout<<"incorrect password";
 }
   return(0);
 }    // end of main

编译器给出了这些错误-----

warning : In function 'void encryptpass(char*)':
line 9 error: array must be initialized with a brace-enclosed initializer
line 9 warning: unused variable 'enpass' [-Wunused-variable]
line 10 error: 'enpass' was not declared in this scope
line 10 error: return-statement with a value, in function returning 'void' [-fpermissive]
warning : In function 'void decryptpass(char*)':
line 17error: array must be initialized with a brace-enclosed initializer
line 17 warning: unused variable 'depass' [-Wunused-variable]
line 18 error: 'depass' was not declared in this scope
line 18 error: return-statement with a value, in function returning 'void' [-fpermissive]
warning : In function 'int main()'
line 25 warning: suggest parentheses around assignment used as truth value [-Wparentheses]

line 31 error: 'enpass' was not declared in this scope
line 36 error: 'pass' was not declared in this scope
line 39 error: 'file' was not declared in this scope
line 43 error: 'depass' was not declared in this scope

Answer 1

您的编译器输出似乎与您的来源不匹配，例如根据编译器，encryptpass的返回类型为void。

第一个错误是因为char empass[10]是一个大小为10的char数组的声明，但是你正在使用它像char值。所以首先在for循环之前声明它：

char empass[10];

然后在for循环中，您将使用

设置编码密码的第i个元素

empass[i] = ++pass[i];

但是，您的代码也在修改传递给函数的密码：++pass[i]将pass[i]增加1。这真的是你想要的吗？

c ++加密和解密源代码

1 个答案: