3/16/2015 - 7:44 PM

Ruby Arrays

Ruby Arrays

# Ruby Arrays

# In our programs we will have to deal with structured lists of data
# For that in Ruby we use the Array class. 

# Arrays being lists, it's natural to want to go through each 
# item in the list. We call this array traversal or iteration.

numbers = [ "One", 2, "Three" ]
puts numbers

# array

numbers = [ "One", 2, "Three" ]

# We can use for to iterate the collection:

for element in numbers
  puts "-> #{element}"

# This approach is not used too much. It is much more common to see:

numbers.each do |element|
  puts "--> #{element}"

# Of course we can modify or mutate our arrays by adding and removing elements. 
# To add elements we can use the shovel operator << or push function. 
# To remove elements we can, for example, use the delete_at function.

my_array = []

my_array << "A"
my_array.push "B"
my_array.push "C"

my_array.delete_at 2

puts my_array


arr.each {|something| puts something.class}

arr.push {'saddd', 'saddd', 'saddd', 'saddd'}

class Item
	def price
		return '3.50'

arr.push {'', '', '', ''}


# Hashes

# A Hash is an associative array. 
# Whereas elements in an array have an order or number associated to them, 
# elements in a hash have a name associated to them. 
# It's basically like a dictionary. You can lookup values by its name or key.

my_hash = {}

my_hash["AST"] = "Asturias"
my_hash[2] = "Galicia"

puts my_hash["AST"]
puts my_hash[2]

puts my_hash

# While

#The while is a construct that runs a chunk of code until a condition is false.

string = ""

# While the string's length is less than 10
while string.size < 10
  # Add an 'a'
  string = string + 'a'

puts "The final string is #{string}"

# Enumerables

# Almost all Ruby collections include a mixin called Enumerable. 
# This is used to provide traversal and searching methods