I have been implementing the Caesar cipher using object oriented programming. The problem is that when I call the encrypted function I get the same message as the user input... The message is not being encrypted properly.
For example if I write "abc" instead of getting "bcd", I am getting "abc". I tried it in C++, the code was working (the logic was fine) but I tried using object-oriented programing in C++ and created three files to separate the code.
Can anyone help or identify any mistake that I may have made?
Executable test File (main function):
#include <iostream>
#include <string>
#include "CyclicShift.h"
using namespace std;
int main()
{
string text;//the string that holds the user input
int key;//key holds the number by which the user wants the alphabets to be shifted
cout << "Enter your phrase: " << endl;
getline(cin, text);//gets the user input ( including spaces and saves it to the variable text)
cout << "Please choose a number(key) for which you wants the alphabets to be shifted: " << endl;
/*Note: the key can either be positive (forward shifting), negative (backward shifting) or zero (no shifting)*/
cin >> key;//User input for number by which alphabets are going to be shifted
const CyclicShift aShift;
cout << "Encrypted Message : " << aShift.Encrypt(text, key) << endl;
//system("Pause");
return 0;
}
Header file .h:
#pragma once
#include <iostream>
#include<string>
//Note: No using "namespace std;" in header files
class CyclicShift
{
private:
char fUpperCase[26];//A-Z
char fLowerCase[26];//a-z
public:
CyclicShift();
std::string& Encrypt(std::string& aOriginalMessage, int &aKey) const;// Function Prototype. This declares Encrypt to be a function that needs one string and one integer variables as arguments. Reference operator & in prototype
};
Source file .cpp:
#include "CyclicShift.h"
#include<iostream>
#include<string>
using namespace std;
CyclicShift::CyclicShift()
{
char fUpperCase[26] = {'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};//Initialization of class member
char fLowerCase[26] = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};//Initialization of class member
}
string& CyclicShift::Encrypt(string& aOriginalMessage, int & aKey) const
{
int z;//z holds the value (int) of the length of the user input ( including spaces)
z = (int)aOriginalMessage.length(); /*give the variable z the value of the user input length and length is normally an unsigned long integer hence
we have to typecast it*/
/*counter that makes it keep looping until it "encrypts" all of the user input (that's why it keeps looping while its less than z)*/
for (int i = 0; i < z; i++)
{
for (int j = 0; j < 26; j++)
{
if (aOriginalMessage[i] == fLowerCase[j] || aOriginalMessage[i] == fUpperCase[j])
{
if (aKey > 0)
{
//another counter that loops forwards key times by incrementing method
for (int counter = 0; counter < aKey; counter++)
{
/*it checks if the letter text[x] is 'z' and if it is 'z' it will make it 'a'*/
if (aOriginalMessage[i] == 'z')
{
aOriginalMessage[i] = 'a';
}
else if (aOriginalMessage[i] == 'Z')
{
aOriginalMessage[i] = 'A';
}
else
{
aOriginalMessage[i]++;
}
}
}
else if (aKey < 0)
{
//another counter that loops backwards key times by decrementing method
for (int counter = 0; counter < abs(aKey); counter++)
{
/*it checks if the letter text[x] is 'a' and if it is 'a' it will make it 'z'*/
if (aOriginalMessage[i] == 'a')
{
aOriginalMessage[i] = 'z';
}
else if (aOriginalMessage[i] == 'A')
{
aOriginalMessage[i] = 'Z';
}
else
{
aOriginalMessage[i]--;
}
}
}
else
{
aOriginalMessage[i];//No alphabet shifts
}
}
else {
continue;
}
break;
}
}
return aOriginalMessage;
}
Above are the three code files of my object-oriented implementation: Testing (main), Header and source .cpp file.
