Iteration
In the first week, you were introduced to state. This week, you were introduced to iteration, one of the more difficult programming constructs to grasp. To reinforce your understanding of iteration, this lab will look at one of the earliest and most widely known encryption techniques known as the Caesar Cipher.
Each letter in the plain text is substituted for a letter from the same alphabet. The new letter chosen depends on the shift number and the direction. The table below shows the results of a backwards shift of three.
If the letter in our plaintext is H, we shift three places to the left (backwards), passing G and F before reaching E. We replace the H in our plaintext with the character E.