Control Flow Lab

Workflow & Submission

  1. Create a repo for this lab.
  2. Start each exercise using snippets in the Sources tab of the Chrome Developer Tools (snippet docs).
  3. Test each snippet individually using at least 2 different inputs.
  4. Copy your snippets into individual files in your repo. Try making a commit for each one you complete.
  5. Push your work to a repo on your GitHub account.
  6. Submit the link to your github repo in the homework submission form.

Exercise 1: Sing!

Hint: Be mindful of infinite loops. They will crash your browser, and you'll lose your snippets! When you're working with a loop that might not end, keep a copy of your code in Sublime Text, too.

  1. Write code that console logs the "Bottles of beer on the wall" song:

     5 bottles of beer on the wall,
 5 bottles of beer!
 Take one down and pass it around,
 4 bottles of beer on the wall!
  • How would you fix "1 bottles of beer"?
  • How would you change "0" to "No more"?
  • Use a JavaScript prompt to ask the user how many verses they want to hear.

Exercise 2: Login

  1. Create a userLogin object with one key for a user's name and one key for the user's password. Just make up a user name and password. Write a code snippet that prompts the user for their password with a message customized to the user. For example, if the user name you created is octocat_rules, the message should be "Enter password for user octocat_rules."

  2. Extend your previous snippet to check whether the password the user gives matches the password in the userLogin object. The snippet should communicate whether the passwords matched to the user with console logs or JavaScript alert.

Bonus: Modify your user login to give the user three chances to enter the correct password.

Exercise 3: Security Questions

  1. Create an array called securityQuestions. Each element of securityQuestions will be an object with two keys: question and expectedAnswer.
  2. Populate (fill) securityQuestions with at least three such objects. Feel free to just make them up. For example, one security question object might be:
     { question: "What was your first pet's name?", expectedAnswer: "FlufferNutter" }
  1. Write code that goes through each of the security questions doing the following:
    • prompt the user with the question
    • check whether the user's input matches the expected answer
       * if the answer does match, ask the next question
 * if the answer doesn't match, stop asking questions and pop up an alert message.

Bonus: Sign Up

Hint: You might find the match method or the search method for JavaScript Strings useful. Both use regular expressions.

  1. Write a code snippet to prompt a user for their email address and check whether an the address looks real (this is called input validation). Hint: what features do valid email addresses share?

  2. Write a code snippet to prompt the user for a password and check whether the password is "strong." You decide what requirements to set for a strong password. If the password is NOT strong, your code should give the user an explanation of what they need to change either through console logs or through alerts.