1608-b-week1.markdown

Module 1 Week 1 Diagnostic

This exercise is intended to help you assess your progress with the concepts and techniques we've covered during the week.

For these questions, write a short snippet of code that meets the requirement. Fill in your answers on a second sheet of paper or in your notebook. In cases where the question mentions a "given" data value, use the variable given to refer to it (instead of re-writing the information).

1. Create a variable called name and assign it to a string containing your name.

2. Given the string "Turing", retrieve the first character

3. Given the string "abcdefghijklmnopqrstuvwxyz", retrieve the last character

4. Given the string "Welcome to the Dungeon", retrieve the substring "Welcome"

5. Find the number of characters in the string "supercalifragilisticexpialidocious"

6. Find the number of words in the string "Coding is gr8"

7. Given 2 strings, "key" and "board", create a new string by concatening them together

8. Create a variable called no_things and assign it to an empty array

9. Create an array of the numbers 1 to 5

10. Given the array ["dog", "cat", "parrot"], retrieve the second element ("cat")

11. Given the array ["dog", "cat", "parrot"], find how many elements appear in the array

12. Create an array containing strings of the names of the 2 students sitting closest to you.

13. Given the array from number 12, print the name of each student.

14. Given the array from number 12, add the name "Jeff" to the end of the list

15. Given the array [1,2,3,4], return a new array of only the even numbers. Then an array of only the odd numbers.

16. Given the following array, retrieve the second element of the first nested array

[
  ["Horace", "Module 1"],
  ["Jeff", "Module 1"],
  ["Rachel", "Module 2"],
  ["Steve", "Module 4"]
]

17. Given the following array, sort the list alphabetically by the names (i.e. the first element of each sub-array)

[
  ["Horace", "Module 1"],
  ["Jeff", "Module 1"],
  ["Rachel", "Module 2"],
  ["Steve", "Module 4"]
]

18. Given the array ["pizza", "casserole", "pie"], remove the last element from the array

19. Create an empty hash

20. Create a hash which associates the key "puppy" with the value "dog"

21. Assign the hash from 20 to a variable. Then add to it a new key "kitten" which points to the value "cat"

22. Given the hash from 21, create an array of the strings "puppy" and "kitten" (don't worry about the order)

23. Given the hash from 21, create an array of the strings "dog" and "cat" (don't worry about the order)

24. Given the array ["Jeff", "Horace", "Josh", "Joanne"], create a new array containing each name in ALL CAPS

25. Given the array ["Jeff", "Horace", "Josh", "Joanne"], create a new array containing only the names that are shorter than 5 characters

26. Given the array [1,2,3,4], add up all the numbers in the list

27. Given the following list of variable names, circle those that are valid ruby local variable names

• TARDIS
• apples
• @height
• 3_blind_mice
• soda_or_pop
• @@x
• $pizza
• best_teacher

28. Given the string "pizza", create an array containing the individual characters, capitalized (i.e. ["P", "I", "Z", "Z", "A"])

29. Given the array ["Jeff", "Horace", "Josh", "Joanne"], create a new array containing only the names that start with "J"

30. Given the following array, retrieve the name of the first instructor who teaches "Module 2"

[
  ["Horace", "Module 1"],
  ["Jeff", "Module 1"],
  ["Rachel", "Module 2"],
  ["Steve", "Module 4"]
]

31. Given the string "turing students love sunlight" replace "sunlight" with "darkness"

32. Given the string "dogs and cats and parrots", replace all instances of the string "and" with "or"

33. Given the array ["dogs", "cats", "parrots"], create the string "dogs and cats and parrots"

1. Create a variable called name and assign it to a string containing your name.
   name = "Alisher"

2. Given the string "Turing", retrieve the first character
   "Turing"[0]

3. Given the string "abcdefghijklmnopqrstuvwxyz", retrieve the last character
   "abcdefghijklmnopqrstuvwxyz"[-1]

4. Given the string "Welcome to the Dungeon", retrieve the substring "Welcome"
   "Welcome to the Dungeon"[0..6]

5. Find the number of characters in the string "supercalifragilisticexpialidocious"
   "supercalifragilisticexpialidocious".length

6. Find the number of words in the string "Coding is gr8"
   truth = "Coding is gr8"
   word_count = truth.split.count

7. Given 2 strings, "key" and "board", create a new string by concatenaing them together
   "key" + "board"

8. Create a variable called no_things and assign it to an empty array
   no_things = []

9. Create an array of the numbers 1 to 5
   numbers = [1, 2, 3, 4, 5]

10. Given the array ["dog", "cat", "parrot"], retrieve the second element ("cat")
    animals = ["dog", "cat", "parrot"]
    animals[1]

11. Given the array ["dog", "cat", "parrot"], find how many elements appear in the array
    animals = ["dog", "cat", "parrot"]
    animals.count

12. Create an array containing strings of the names of the 2 students sitting closest to you.
    names = ["Anna", "Daniel"]

13. Given the array from number 12, print the name of each student.
    names = ["Anna", "Daniel"]
    puts names

14. Given the array from number 12, add the name "Jeff" to the end of the list
    names << "Jeff" or names.push("Jeff")

15. Given the array [1,2,3,4], return a new array of only the even numbers. Then an array of only the odd numbers.
    numbers = [1,2,3,4]
    even_numbers = numbers.map do |number|
    number.even?
    end

    odd_numbers = numbers.map do |number|
    number.odd?
    end

16. Given the following array, retrieve the second element of the first nested array

people = [
["Horace", "Module 1"],
["Jeff", "Module 1"],
["Rachel", "Module 2"],
["Steve", "Module 4"]
]
people[0][1]
17. Given the following array, sort the list alphabetically by the names (i.e. the first element of each sub-array)

people = [
["Horace", "Module 1"],
["Jeff", "Module 1"],
["Rachel", "Module 2"],
["Steve", "Module 4"]
]
people.sort
18. Given the array ["pizza", "casserole", "pie"], remove the last element from the array
things = ["pizza", "casserole", "pie"]
things.pop
19. Create an empty hash
dictionary = {}
20. Create a hash which associates the key "puppy" with the value "dog"
animals = {"puppy" => "dog"}
21. Assign the hash from 20 to a variable. Then add to it a new key "kitten" which points to the value "cat"
animals = {"puppy" => "dog"}
animals.store("kitten", "cat")
22. Given the hash from 21, create an array of the strings "puppy" and "kitten" (don't worry about the order)
animals.keys
23. Given the hash from 21, create an array of the strings "dog" and "cat" (don't worry about the order)
animals.values
24. Given the array ["Jeff", "Horace", "Josh", "Joanne"], create a new array containing each name in ALL CAPS
associates = ["Jeff", "Horace", "Josh", "Joanne"]
associates_caps = associates.map do |associate|
associate.capitalize
end
25. Given the array ["Jeff", "Horace", "Josh", "Joanne"], create a new array containing only the names that are shorter than 5 characters
associates = ["Jeff", "Horace", "Josh", "Joanne"]
associates_caps = associates.map do |associate|
associate if associate.length < 5
end
26. Given the array [1,2,3,4], add up all the numbers in the list
numbers = [1,2,3,4]
sum = 0
numbers.each do |number|
sum += number
end
return sum
27. Given the following list of variable names, circle those that are valid ruby local variable names

TARDIS
apples => valid
@height
3_blind_mice
soda_or_pop
@@x
$pizza
best_teacher => valid
28. Given the string "pizza", create an array containing the individual characters, capitalized (i.e. ["P", "I", "Z", "Z", "A"])
word = "pizza"
word.upcase.chars or word.upcase.split("")
29. Given the array ["Jeff", "Horace", "Josh", "Joanne"], create a new array containing only the names that start with "J"
associates = ["Jeff", "Horace", "Josh", "Joanne"]
associates_with_j = associates.map do |associate|
associate if associate.start_with?("J")
end
30. Given the following array, retrieve the name of the first instructor who teaches "Module 2"

instructors = [
["Horace", "Module 1"],
["Jeff", "Module 1"],
["Rachel", "Module 2"],
["Steve", "Module 4"]
]
instructors[2][0]
31. Given the string "turing students love sunlight" replace "sunlight" with "darkness"
truth = "turing students love sunlight"
deception = truth.sub("sunlight", "darkness")
32. Given the string "dogs and cats and parrots", replace all instances of the string "and" with "or"
"dogs and cats and parrots".sub("and", "or")
33. Given the array ["dogs", "cats", "parrots"], create the string "dogs and cats and parrots"
friends = "dogs and cats and parrots"
friends.join(" and ")
or
sentence = ""
friends.each do |friend|
sentence << friend + " and "
end
return sentence