Question

Please solve the following programming exercise using c++:

Write a class named EncryptableString that is derived from the STL string class. The EncryptableString class adds a member function:

  void encrypt()  

which encrypts the string contained in the object by replacing each letter with its successor in the ASCII ordering. (For example the string baa encrypted would become cbb. Encrypt it again and the string would become dcc.) Assume that the only characters to be encrypted in an EncryptableString object are letters (a → z and A → Z), and numbers (0 → 9), and that the successor of 'z' is 'a', the successor of 'Z' is 'A', and the successor of '9' is '0'. Other characters do not need to be encrypted, such as spaces and punctuation.

Test your class with a program that prompts the user to enter strings to be encrypted, then prints the encrypted strings:

Holy Moly!
San Diego Zoo
The cost is $25.89.
Go away - unless you have tacos.
No one can make you feel inferior without your consent.

Please submit all program files, print screens or screen snippets of the output of your programs

Answer 1

 #include <iostream> using namespace std; class EncryptableString { private: string str; public: EncryptableString(string s) { str = s; } void encrypt() { int i; string e_string = ""; for(i=0;i<str.length();i++) { char c = str[i]; if(c=='z') c='a'; else if(c=='Z') c='Z'; else if(c=='9') c='0'; else if(isalnum(c)) c = c + 1; e_string += c; } str = e_string; } void display() { cout<<str<<endl; } }; int main() { string input; cout << "Enter string" << endl; getline(cin,input); EncryptableString es = EncryptableString(input); es.encrypt(); es.display(); return 0; }