gistfile1.rb

# Instance Variable
@people = [] # Array

# Local Variable
age = 32 # Integer

weight = 195.6 # Float

# = means assignment
person = {} # Hash

			# String
word = "hello".upcase # method execution

# String interpolation
"#{word} there #{age}" # used with strings
# This is NOT string interpolation
# notice the single quotes. This is literal
'#{word} there #{age}'

def thing
	# this is a method definition
end

# class
class Human # constant
end

# variables can change at any time
# constants can NOT change EVAR!!!

# < SomeConstant means inheritance
class Cat < Animal
	# 2 types of methods
	# Instance methods
	# Class methods

	# this is instance method
	def walk
		# instance methods only affect that instance
		puts "walking"
	end
end

# Object Instantiation
kitty = Cat.new #new is a class method. it's called on the class Cat

# kitty is an instance of Cat object
kitty.walk #walk is an instance method. 
					#it's called on the instance of the Cat class 

# person is a hash
# hashes are key/value pairs
# adding a new key/vaule to an existing hash
person["name"] = "Jeremy"

# defining a new hash with default vaules
game = {"name" => "Mega Man"}

# @people is an array
# arrays are collections of objects
# arrays use a 0 based index
@people[0] = "Alex" # assign the value "Alex" to the index 0 in the array
@people << "Jeremy" # << is the put stuff into the array operator
@people.push("John") #push is an array method that does the same thing

# 1 is the 2nd index because 0,1,2,3,4,etc...
puts @people[1] # print out the name in the 2nd index of the array

# each is an iterator method that arrays have
@people.each do |name|
	# name is a local variable inside of this code block
	puts name
end #iterators that use the keyword "do" need an "end"

					# inside the parenthesis is the arguments
					# this method has 2 arguments
def encrypt(string, number)
	# string is a local variable inside this method
	# number is a local variable inside this method
end
				# call the method, and pass 2 arguments
encrypt("hello", 10)

# the dot dot means it's a Range object
1..100 # a range of numbers 1 to 100
# convert the range to an array
(1..100).to_a

# multi-dimentional array
grid = [['a',1], ['b',2], ['c',3]]

cipher = Hash[grid] # convert multi-dimentional array to hash
cipher # {'a' => 1, 'b' => 2, 'c' => 3}



class Board
	def initialize
		# set initial values for the board object
		# when you instantiate the class
		# ruby runs this method when you call Board.new
	end
end

#notice the File is using class methods, and file is using instance methods
# the ? means the method will return true / false
File.exists?('path/to/file.txt')
# open the file in read only mode
file = File.open('path/to/file.txt')
# http://apidock.com/ruby/IO for other modes
file.read #read 1 line of the file
file.close # close the file