diff options
| -rw-r--r-- | ruby.html.markdown | 59 |
1 files changed, 31 insertions, 28 deletions
diff --git a/ruby.html.markdown b/ruby.html.markdown index 44b0e46c..62db549c 100644 --- a/ruby.html.markdown +++ b/ruby.html.markdown @@ -13,8 +13,13 @@ No-one uses them You shouldn't either =end +# First and foremost: Everything is an object. -3 #=> 3 +# Numbers are objects + +3.class #=> Fixnum + +3.to_s #=> "3" # Some basic arithmetic @@ -23,15 +28,24 @@ You shouldn't either 10 * 2 #=> 20 35 / 5 #=> 7 -# Special values -nil #=> Nothing to see here -true #=> truth -false #=> falsehood +# Special values are objects +nil # Nothing to see here +true # truth +false # falsehood + +nil.class #=> NilClass +true.class #=> TrueClass +false.class #=> FalseClass # Equality 1 == 1 #=> true 2 == 1 #=> false +# apart from false itself, nil is the only other 'falsey' value + +nil == false #=> true +0 == false #=> false + # Inequality 1 != 1 #=> false 2 != 1 #=> true @@ -44,8 +58,10 @@ false #=> falsehood 2 <= 2 #=> true 2 >= 2 #=> true -'I am a string' -"I am a string too" +# Strings are objects + +'I am a string'.class #=> String +"I am a string too".class #=> String placeholder = "use string interpolation" "I can #{placeholder} when using double quoted strings" @@ -57,6 +73,7 @@ puts "I'm printing!" # Variables x = 25 #=> 25 +x #=> 25 # Note that assignment returns the value assigned # This means you can do multiple assignment: @@ -72,17 +89,19 @@ snake_case = true path_to_project_root = '/good/name/' path = '/bad/name/' -# Symbols +# Symbols (are objects) # Symbols are immutable, reusable constants represented internally by an integer value # They're often used instead of strings to efficiently convey specific, meaningful values +:pending.class #=> Symbol + status = :pending status == :pending #=> true status == 'pending' #=> false -position = :left +status == :approved #=> false # Arrays @@ -107,26 +126,9 @@ array[2, 4] #=> [3, 4, 5] # Or with a range array[1..3] #=> [2, 3, 4] -# Add to the end of an array like this +# Add to an array like this array << 6 #=> [1, 2, 3, 4, 5, 6] -# Or like this -array.push 7 #=> [1, 2, 3, 4, 5, 6, 7] - -# Or to the beginning like this -array.unshift 0 #=> [0, 1, 2, 3, 4, 5, 6, 7] - -# Remove the first item in an array - -array.shift #=> [1, 2, 3, 4, 5, 6, 7] - -# Or the last - -array.pop #=> [1, 2, 3, 4, 5, 6] - -# Note that push and pop do the opposite of each other -# Shift and unshift are the same. - # Hashes are Ruby's primary dictionary with keys/value pairs. # Hashes are denoted with curly braces: hash = {'color' => 'green', 'number' => 5} @@ -152,7 +154,7 @@ new_hash = { defcon: 3, action: true} new_hash.keys #=> [:defcon, :action] # Tip: Both Arrays and Hashes are Enumerable -# This means they share a lot of useful methods +# This means they share a lot of useful methods such as each, map, count, and more # Control structures @@ -197,6 +199,7 @@ end #=> iteration 5 grade = 'B' + case grade when 'A' puts "Way to go kiddo" |