Exercise
Encrypter & Decrypter
Objetive
Create a class "Encrypter" to encrypt and decrypt text.
It will have a "Encrypt" method, which will receive a string and return another string. It will be a static method, so that we do not need to create any object of type "Encrypter".
There will be also a "Decrypt" method.
In this first approach, the encryption method will be a very simple one: to encrypt we will add 1 to each character, so that "Hello" would become "Ipmb", and to decrypt we would subtract 1 to each character.
An example of use might be
string newText = Encrypter.Encrypt("Hola");
Code
Imports System
Namespace Program
Class Encrypter
Public Shared Function Encrypt(ByVal text As String) As String
Dim letterInt As Integer = 0
Dim letter As Char = " "c
Dim textEncripted As String = ""
For i As Integer = 0 To text.Length - 1
letterInt = CInt(text(i)) + 1
letter = ChrW(letterInt)
textEncripted += letter.ToString()
Next
Return textEncripted
End Function
Public Shared Function Decrypt(ByVal text As String) As String
Dim letterInt As Integer = 0
Dim letter As Char = " "c
Dim textDecripted As String = ""
For i As Integer = 0 To text.Length - 1
letterInt = CInt(text(i)) - 1
letter = ChrW(letterInt)
textDecripted += letter.ToString()
Next
Return textDecripted
End Function
End Class
Class TextEncripted
Private Shared Sub Main()
Dim debug As Boolean = True
Dim newText As String = Encrypter.Encrypt("Hola")
Console.WriteLine("Text encripted: {0}", newText)
Dim TextDescripted As String = Encrypter.Decrypt(newText)
Console.WriteLine("Text Decripted: {0}", TextDescripted)
If debug Then Console.ReadLine()
End Sub
End Class
End Namespace