9.10. Studio: Loops

Now that we’ve launched our shuttle, let’s use loops (iteration) to automate some tasks.

9.10.1. Part A (Self-destruct system)

If the shuttle gets hijacked by space pirates, the astronauts can activate a self-destruct sequence to provide some drama for the viewers at home.

In order to prevent a rogue astronaut from activating the code, it takes two crew members to begin the countdown. Each person must enter a different code, after which the computer will “zip” them together before overloading the engines.

For the purposes of easier (human) readability, try using the following console method Console.Write. How is it different from Console.WriteLine?

  1. Construct a for loop that combines two strings together, alternating the characters from each source.


    1. If string partOne = "1234" and string partTwo = "5678", then the output will be “15263748”.

    2. If string code1 = "ABCDEF" and string code2 = "notyet", then the output will be “AnBoCtDyEeFt”.

    3. If string ka = "LoOt" and string blam = "oku!", then the output will be "LookOut!".

    Code it at replt.it

9.10.2. Part B (Put dinner together)

  1. First, initialize variables to store the following arrays. Remember to use descriptive names.

    • Protein options:

      {"chicken", "pork", "tofu", "beef", "fish", "beans"}
    • Grain options:

      {"rice", "pasta", "corn", "potato", "quinoa", "crackers"}
    • Vegetable options:

      {"peas", "green beans", "kale", "edamame", "broccoli", "asparagus"}
    • Beverage options:

      {"juice", "milk", "water", "soy milk", "soda", "tea"}
    • Dessert options

      {"apple", "banana", "more kale", "ice cream", "chocolate", "kiwi"}

Code it at replt.it

  1. Use a for loop to assemble 6 meals.

    1. The meals must include one item from each of the source arrays.

    2. Each ingredient can only be used ONCE.

    3. Print out each meal.

9.10.3. Part B (Refinements)

Update your code from part A to add user input and validation.

  1. Using a while loop, ask the user to select the number of meals to assemble. Validate the input to make sure it is an integer from 1 - 6.

  2. Refactor your for loop to use the user input to select and print that many meals.

  3. Bonus Mission: (Optional) To enhance your learning, modify your code to:

    1. Use string formatting to print something more interesting than a list of “chicken”, “rice”, “peas”, “juice”, “apple” for the meal outputs.

    2. Create a string array of labels to describe each item in a meal. Use a nested loop print your each item with the appropriate label.

    3. Modify your code to check each meal for kale. If present, after the meal output add, “Don’t worry, you can have double chocolate tomorrow.”

Bon appetit!