8.6. Studio: Strings and Arrays

Strings are ordered collections of characters, which are strings of length 1. The characters in a string can be accessed using bracket notation.

Arrays are ordered collections of items, which can be strings, numbers, other arrays, etc. The items/elements/entries stored in an array can be accessed using bracket notation.

Strings are immutable, whereas arrays can be changed.

Strings and arrays have properties and methods that allow us to easily perform some useful actions.

8.6.1. Before You Start

If you are enrolled in a LaunchCode program, access this studio by following the repl.it classroom links posted in your class at learn.launchcode.org.

If you are working through this material on your own, use the repl.it links contained on this page.

8.6.2. String Modification

Use string methods to convert a word into pseudo-pig latin.

  1. Remove the first three characters from a string and add them to the end. Ex: 'LaunchCode' becomes 'nchCodeLau'. Use a template literal to print the original and modified string in a descriptive phrase.
  2. Modify your code to accept user input. Query the user to enter the number of letters that will be relocated.
  3. Add validation to your code to deal with user inputs that are longer than the word. In such cases, default to moving 3 characters. Also, the template literal should note the error.

Code it at repl.it

8.6.3. Array and String Conversion

The split and join methods convert back and forth between strings and arrays. Use delimiters as reference points to split a string into an array, then modify the array and convert it back to a printable string.

  1. For a given string, use the includes method to check to see if the words are separated by commas (,), semicolons (;) or just spaces.
  2. If the string uses commas to separate the words, split it into an array, reverse the entries, and then join the array into a new comma separated string.
  3. If the string uses semicolons to separate the words, split it into an array, alphabetize the entries, and then join the array into a new comma separated string.
  4. If the string uses spaces to separate the words, split it into an array, reverse alphabetize the entries, and then join the array into a new space separated string.
  5. Consider: What if the string uses 'comma spaces' (, ) to separate the list? Modify your code to produce the same result as part "b", making sure that the extra spaces are NOT part of the final string.

Code it at repl.it

8.6.4. Bonus Mission: Multi-dimensional Arrays

Arrays can store other arrays!

  1. The cargo hold in our shuttle contains several smaller storage spaces. Use split to convert the following strings into four cabinet arrays. Alphabetize the contents of each cabinet.
    1. "water bottles, meal packs, snacks, chocolate"
    2. "space suits, jet packs, tool belts, thermal detonators"
    3. "parrots, cats, moose, alien eggs"
    4. "blankets, pillows, eyepatches, alarm clocks"
  2. Initialize a cargoHold array and add the cabinet arrays to it. Print cargoHold to verify its structure.
  3. Query the user to select a cabinet (0-3) in the cargoHold.
  4. Use bracket notation and a template literal to display the contents of the selected cabinet. If the user entered an invalid number, print an error message instead.
  5. Bonus to the Bonus: Modify the code to query the user for BOTH a cabinet in cargoHold AND a particular item. Use the includes method to check if the cabinet contains the selected item, then print "Cabinet ____ DOES/DOES NOT contain ____."

Code it at repl.it