Create a git branch called methods-lesson and put the following ruby programs in it.

(1) Write a method that returns in an array all the numbers between 1 and 100 that are divisible by 2 or 3 or 5. Then call the method in your program and print out what it returns. Call the program divisible.rb.

(2) Write a program hangman.rb that contains a function called hangman. The function's parameters are a word and an array of letters. It returns a string showing the letters that have been guessed. Call the function from within your program so that you know that it works.

Example: hangman("bob",["b"]) should evaluate to "b_b" Example: hangman("alphabet",["a","h"]) should return "a__ha___"

(3) Write a program that collects 5 keys and 5 values from the user, and stores them in a hash. Write a function that accepts the hash as optional parameters and prints out an array of keys and an array of values. Call the function within your program so you know it works. (Question: Can you find online information on Ruby hash methods that will help with this function?) Call this program hash_to_array.rb.

(4) Create a program sums.rb with two classes.

(a) a class called Sum1 with an initialize method that takes two parameters and sets the instance variable total to the sum of the two. Include a line at the top of the class:

attr_accessor :total

(b) a class called Sum2 with an initialize method that takes two parameters a and b and sets the instance variable a to the parameter a and the instance variable b to the parameter b. Create a method new_total inside Sum2 that returns the sum of the instance variables a and b.

(c) In the mainline program, create instances of Sum1 and Sum2, passing 5 and 6 as parameters on the new statement. Print out the total for Sum1. Print out the new_total for Sum2.

(5) The ruby array sort method can use a block to sort various arrays. The block must compare between two elements of the array, a and b. If a<b, it should evaluate to -1. If a==b, it should evaluate to 0. And if a>b, it should evaluate to 1. Here is the start of a program, which you should call sort_blocks.rb.

class Book
  attr_reader :author, :title, :count
  def initialize(author,title,count)
    @author = author
    @title = title
    @count = count
  end
  def to_s
    "author: #{author} title: #{title} count: #{count}"
  end
end

book_array = []
book_array.push(Book.new("Beatrice Potter","Peter Rabbit",25))
book_array.push(Book.new("Henry Fielding","Tom Jones",12))
book_array.push(Book.new("Bob Woodward","All the President's Men",30))

puts "Sorting alphabetically by author"

new_array = book_array.sort do |a,b|
  author1 = a.author.downcase
  author2 = b.author.downcase
  author1 <=> author2
  # if author1 > author2
  #   1
  # elsif author1 < author2
  #   -1
  # else
  #   0
  # end
end
puts new_array

Note the use of the spaceship operator <=>. It does what the commented out lines do, but on one line.

Add to this program. Add additional calls to book_array.sort that pass blocks. For your first call to sort, pass a block so that the array is sorted in order of title, and print out the array. For your second call to sort, pass a block so that the array is sorted in order of copies, and print out the array.

(6) Create a program block_function.rb. It should have a function do_calc that calls a block using a yield statement. The yield statement will pass the numbers 7 and 9 to a block, and then will print out the result. Call the do_calc function twice in your program. The first time, pass a block that adds the two numbers. The second time, pass a block that multiplies the two numbers. Your program should print out 16 and 63.

Then push your changes to github and issue a pull request.