Imagine a screen where a user inputs a meal that they've eaten. If the user taps a "save" button without adding any food, you might want to prompt the user that they haven't actually added anything. Using the Food struct and the text fields provided below, create a function called logFood that takes no parameters and returns an optional Food object. Inside the body of the function, use a guard statement to unwrap the text property of food TextField and calories TextField. In addition to unwrapping calories TextField, you'll need to create and unwrap a new variable that initializes an Int from the text in caloriesTextField. If any of this fails, return nil. After the guard statement, create and return a Food object.

1. ask the user how many questions are in the quiz. 2. ask the user to enter the key (that is, the correct answers). there should be one answer for each question in the quiz, and each answer should be an integer. e. g., 34 7 13 100 81 3 9 10 321 12 might be the key for a 10-question quiz. you will need to store the key in an array. 3. ask the user to enter the answers for the quiz to be graded. there needs to be one answer for each question. note that these answers do not need to be stored; each answer can simply be compared to the key as it is entered. 4. when the user has entered all of the answers to be graded, print the number correct and the percent correct. 5. add a loop so that the user can grade any number of quizzes with a single key. after the results have been printed for each quiz, ask "grade another quiz? (y/n)." note: you only have one array (the key). you are not creating a new key for each set of quiz answers.