diff options
Diffstat (limited to 'ruby.html.markdown')
-rw-r--r-- | ruby.html.markdown | 44 |
1 files changed, 29 insertions, 15 deletions
diff --git a/ruby.html.markdown b/ruby.html.markdown index 861a94ad..3a233d98 100644 --- a/ruby.html.markdown +++ b/ruby.html.markdown @@ -5,6 +5,8 @@ contributors: - ["David Underwood", "http://theflyingdeveloper.com"] - ["Joel Walden", "http://joelwalden.net"] - ["Luke Holder", "http://twitter.com/lukeholder"] + - ["Tristan Hume", "http://thume.ca/"] + - ["Nick LaMuro", "https://github.com/NickLaMuro"] --- ```ruby @@ -34,7 +36,7 @@ You shouldn't either # Arithmetic is just syntactic sugar # for calling a method on an object 1.+(3) #=> 4 -10.* 5 #=> 50 +10.* 5 #=> 50 # Special values are objects nil # Nothing to see here @@ -116,11 +118,11 @@ status == :approved #=> false # Arrays # This is an array -[1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5] +array = [1, 2, 3, 4, 5] #=> [1, 2, 3, 4, 5] # Arrays can contain different types of items -array = [1, "hello", false] #=> => [1, "hello", false] +[1, "hello", false] #=> [1, "hello", false] # Arrays can be indexed # From the front @@ -158,11 +160,6 @@ hash['number'] #=> 5 # Asking a hash for a key that doesn't exist returns nil: hash['nothing here'] #=> nil -# Iterate over hashes with the #each method: -hash.each do |k, v| - puts "#{k} is #{v}" -end - # Since Ruby 1.9, there's a special syntax when using symbols as keys: new_hash = { defcon: 3, action: true} @@ -177,9 +174,9 @@ new_hash.keys #=> [:defcon, :action] if true "if statement" elsif false - "else if, optional" + "else if, optional" else - "else, also optional" + "else, also optional" end for counter in 1..5 @@ -191,9 +188,15 @@ end #=> iteration 4 #=> iteration 5 -# HOWEVER -# No-one uses for loops -# Use `each` instead, like this: +# HOWEVER, No-one uses for loops. +# Instead you should use the "each" method and pass it a block. +# A block is a bunch of code that you can pass to a method like "each". +# It is analogous to lambdas, anonymous functions or closures in other +# programming languages. +# +# The "each" method of a range runs the block once for each element of the range. +# The block is passed a counter as a parameter. +# Calling the "each" method with a block looks like this: (1..5).each do |counter| puts "iteration #{counter}" @@ -204,6 +207,17 @@ end #=> iteration 4 #=> iteration 5 +# You can also surround blocks in curly brackets: +(1..5).each {|counter| puts "iteration #{counter}"} + +# The contents of data structures can also be iterated using each. +array.each do |element| + puts "#{element} is part of the array" +end +hash.each do |key, value| + puts "#{key} is #{value}" +end + counter = 1 while counter <= 5 do puts "iteration #{counter}" @@ -228,7 +242,7 @@ when 'D' puts "Scraping through" when 'F' puts "You failed!" -else +else puts "Alternative grading system, eh?" end @@ -238,7 +252,7 @@ def double(x) x * 2 end -# Functions (and all blocks) implcitly return the value of the last statement +# Functions (and all blocks) implicitly return the value of the last statement double(2) #=> 4 # Parentheses are optional where the result is unambiguous |