homework.md

WDI Homework - April 8, 2013

Array and Hash access

Given the following data structure:

a = ["Anil", "Erik", "Jonathan"]

• How would you return the string "Erik"?
• How would you add your name to the array?

Given the following data structure:

h = {0 => "Zero", 1 => "One", :two => "Two", "two" => 2}

• How would you return the string "One"?
• How would you return the string "Two"?
• How would you return the number 2?
• How would you add {3 => "Three"} to the hash?
• How would you add {:four => 4} to the hash?

Given the following data structure:

is = {true => "It's true!", false => "It's false"}

• What is the return value of is[2 + 2 == 4]?
• What is the return value of is["Erik" == "Jonathan"]?
• What is the return value of is[9 > 10]?
• What is the return value of is[0]?
• What is the return value of is["Erik"]?

Given the following data structure:

users = {
  "Jonathan" => {
    :twitter => "tronathan",
    :favorite_numbers => [12, 42, 75],
  },
  "Erik" => {
    :twitter => "sferik",
    :favorite_numbers => [8, 12, 24],
  },
  "Anil" => {
    :twitter => "bridgpal",
    :favorite_numbers => [12, 14, 85],
  },
}

• How would you access Jonathan's Twitter handle (i.e. the string "tronathan")?
• How would you add the number 7 to Erik's favorite numbers?
• How would you add yourself to the users hash?
• How would you return the array of Erik's favorite numbers?
• How would you return the smallest of Erik's favorite numbers?
• How would you return an array of Anil's favorite numbers that are also even?
• How would you return an array of the favorite numbers common to all users?
• How would you return an array containing all users' favorite numbers, sorted, and excluding duplicates?