Computer should generate 4 random numbers from 1 - 9 as the "Secret Code".
User should be prompted for their guess of those four numbers.
After they provide their full guess, the user is told how many are correct.
As long as the user does not get all four correct, they keep getting asked for their guess.
After the user finally gets all of them correct (yes - all four), they are congratulated and then told how many tries it took them.