ruby_quiz_1.md

1. What is the difference between a local variable, and an instance variable? local to local, and instance to where ever
2. What is the datatype of "DevPoint Labs"? string
3. Assign the number 10 to the local variable n. N = 10
4. Assign your name to the local variable name. name = "justin"
5. What is an Array? a collection of data with a 0 based index
6. Give an example of when you’d use an Array. when listing items
7. What is a method? naming a set of instrucitons
8. Name 3 iterator methods for an Array. each, sort, split
9. Name 3 methods for a String. .chomp .reverse .upcase
10. What datatype does 5 / 2 return? fixum
11. What is a Hash? key based index using {}
12. Give an example of when you’d use a Hash. like an array but more specific
13. What is a class? classes are blueprints for how objects are created
14. True or False; A class is a constant. true
15. true and false are called what? boolean
16. Write 4 conditional operators.

• / + -

17. Create a method called bucket that returns an empty array. def bucket e = [ ] end

18. Name 6 ruby special keywords. (a keyword is a word that already has a special meaning) class, def, end, elsif, else, rescue

19. How would you convert a number into a string? num.to_s

20. How would you convert a string into a number? "4".to_i

21. What is class inheritance? relation between two classes. Humans < Society

22. What are modules used for? grouping together methods, classes and contants. googs

23. What is a gem? code in a package shipped and ready to expedite some mutha fucking code

24. Name 4 gems, and their purposes. sinarta - ruby in html - small apps rails - build fast apps quickly gosu - 2d and musical development. i wonder if we use clojure, and overtone with ruby pry - used for debugging. still need help with debugging

25. What are comments used for in programming? sudo code, and remembering what was written

26. In Ruby, only 2 things evaluate to false. What are they? false, 0

27. Write 2 comparison operators. || && and these the same as conditonal as well?

28. Write the code for “ if dave’s age is greater than or equal to 21” if daves_age >= 5 puts "drink more beer" end

29. Instantiate a Car class. c = Car.new

30. What is a method chain? adding two or more methods

31. How would you capitalize and reverse a string then print it out to the console? "justin".capitalize.reverse

32. What is a method to add an object to an array?

33. How would you add an object to a hash?

34. What are 2 valid datatypes of keys for a hash?

35. What is a writer method? creating new file to write

36. What is a reader method? reads only from the beginning of the file

37. There are 4 types of variables. What are they? local, @instance, @@class, $global

38. What does the question mark at the end of a method in ruby mean?

39. What’s a common way to debug your code? using pry? honestly, I don't know.

40. How would you return the string "two" from this array? arr = ["one", "two", "three"] arr[1]

41. How would you return the string "DevPoint" from this hash? hsh = {:name => "DevPoint"}

42. What is the datatype for :age? symbol

43. What is the datatype for -36.98? float

44. What is the datatype for [1, 2, 3]? array

45. What is the datatype for "BOOM goes the dynamite"? string

46. What is the datatype for 123412? fixum

47. What is the datatype for {:food => "burger"}? sting interpolation

48. What is the datatype for false? false

49. What is the purpose of nil? 0 nothing.

50. How would you print out the current date? Time.now

51. How would you print out just the current year without using a Fixnum? time.year?

52. What is String interpolation? allowing ruby code to appear within a string. #{1 + 2}

53. What is String concatenation? with you take two or more strings and add them together

54. What does OOP stand for? object oriented programming

55. What does instantiation mean? creating objects of different types.

56. What is the name of the method that is called every time an object is instantiated? in order to start using the object, it must first be initaizled, so instance variable

57. What are arguments? passing ruby code in ()

58. How do you pass an argument? with variables

59. Write a method called eat that has an argument food with a default value of "cheese". request some help

60. What is a loop? loops are used to execute the smae block of code for a specific number of times. googs

61. How long has ruby been around? 19 years

62. How are you doing on this quiz so far? mind spun

63. Is anyone else hungry? actually, I am. I was, just at micky d's. college budget for a 34 year older, though I do feel like going out and grabbing a beer

64. What are the pipe characters used for in a block? pass in a variable

65. What is the difference between single quote strings and double quote strings? nothing

66. Name some rules for naming a method? used to bunlde one or more repeatable statements. begin with lower case letters. should be defined before calling them. googs, just saying.

67. How can you tell if a method is an instance or class method? class methods are methods that are called on a class and instance methods are methods called on an instance of a class. googs

68. In an instance method, what is self? self is whatever the instance method is in

69. How do you add a dependency to a file?

70. I have a text file called names.txt. Each name is on it's own line. How would you print all the names in the file?

71. When a method defines an argument that has a asterisk in front of a variable name, what is that asterisk referred to? e.g. def thing(*stuff)

72. When a method defines an argument that has an ampersand in front of a variable name, what is that ampersand and variable name collectivly called? e.g. def thing(&stuff)

73. What is it called when you see the do and end keywords together? block

74. What does DRY stand for? dont repeat yourself

75. What does DSL stand for? domain specfic language

76. This question left blank intentionally. why?

77. What does MRI stand for? matz's ruby interper

78. What is the difference between JRuby and MRI? they seem comparabe, though one might be faster than the other.

79. What would you use RubyMotion for? quickly lets one develop and test ios, and osx apps for iphone

80. Does your head hurt? no, but my head is spinning.

3- You can't use a capital letter for a variable name.
8- split is not a method on array
16- those are math operators, not conditional operators
27- 0 returns true in ruby. false and nil are what return false
33- << or push or assigning a value to an index are 3 ways to do this
34- assign a value to the key like hash[:name] = "Jeremy"
35- string and symbols
36- a method to write a value to an attribute
37- a method to read a value from an attribute
39- this method will return a boolean
42- hsh[:name]
48- string interpolation isn't a datatype. The answer is hash
52- It would be Time.now.year
57- the name of the method is initialize
60- def eat(food="cheese"); end
66- there is a difference, look at string interpolation