Update AssessmentPartThree.java

src/AssessmentPartThree.java

-
-public class AssessmentPartThree {
-
-	// The simplest form of encryption is the rotation cipher (also known as Caeser's Cipher)
-	// An offset value is chosen to encrypt a message. Each letter is replaced by the
-	// letter that that number of places away from it.
-	// So if an offset value of 1 is chosen, each letter is replaced by the one after it
-	// - so a becomes b, b becomes c, etc
-	// If a value of -2 is chosen a becomes y, b becomes z and so on
-	
-	 public char enryptedCharacter(char theChar, int theOffset)
-	 {
-		 // 05 - encryptedCharacter
-		 // Complete this method so that it returns the encrypted character for
-		 // theChar when and offset of theOffset is used
-		 // So if theChar='m' and theOffset is 3 the method will return 'p'
-		 // Lower case characters remain lower case, upper case remain upper case
-		 // Any other characters are returned unchanged
-		 
-		 return 'a';
-	 }
-	 
-	 public String encryptedString(String theMessage, int theOffset)
-	 {
-		 // 06 - encryptedMessage
-		 // Complete this method so that it uses encryptedCharacter to 
-		 // return the encrypted version of theMessage using theOffset
-		 
-		 return "Encryptred message";
-	 }
-	
-}
+
+
+public class AssessmentPartThree {
+
+	// The simplest form of encryption is the rotation cipher (also known as
+	// Caeser's Cipher)
+	// An offset value is chosen to encrypt a message. Each letter is replaced by
+	// the
+	// letter that that number of places away from it.
+	// So if an offset value of 1 is chosen, each letter is replaced by the one
+	// after it
+	// - so a becomes b, b becomes c, etc
+	// If a value of -2 is chosen a becomes y, b becomes z and so on
+
+	public char enryptedCharacter(char theChar, int theOffset) {
+		// 05 - encryptedCharacter
+		// Complete this method so that it returns the encrypted character for
+		// theChar when and offset of theOffset is used
+		// So if theChar='m' and theOffset is 3 the method will return 'p'
+		// Lower case characters remain lower case, upper case remain upper case
+		// Any other characters are returned unchanged
+		char Encrypted = 0;
+
+		if (Character.isDigit(theChar)) { // checks to see if a character of theChar is a number
+			return theChar; // if it isn't fully made of letters it returns the original value of theChar
+		} else { // if it was fully letters it goes to this
+			char Value = (char) (theChar + theOffset); // adds theChar value and the offset and sets this as a variable
+			if (Value > 'z') // if the value of "Value" is more then the ASCII value of 'z'(122)
+				Encrypted += (char) (Value) - (26 - theOffset); // if the value is above the max it -26 to get it back
+																// to 'a'
+																// and goes up from there.
+			else // if test isn't bigger then 'z'
+				Encrypted += (char) (Value); // it will just add the offset since the values are in range
+		}
+		return Encrypted;
+	}
+
+	public String encryptedString(String theMessage, int theOffset) {
+		StringBuilder Encrypted = new StringBuilder();	// builds the string which will be returned at the end	
+        for (char i : theMessage.toCharArray()) { //sets the value of i to the values in theMessage, in char form
+            if (Character.isLetter(i)) { //chescks to see if the character is a letter
+                if (Character.isUpperCase(i)) { //checks to see if the character is an uppercase letter
+                	Encrypted.append((char) ('A' + (i - 'A' + theOffset % 26 + 26) % 26 )); // if it is an upercase letter it will change the character like this
+                } else { // if its not uppercase
+                	Encrypted.append((char) ('a' + (i - 'a' + theOffset % 26 + 26) % 26 )); //if it is an lowercase letter it will change the character like this
+                }
+            } else { //if the character isnt a letter it will leave it unchanged
+            	Encrypted.append(i);
+            }
+        }
+        return Encrypted.toString(); //returns the Array in a stringform
+    }
+}