diff options
| -rw-r--r-- | python.html.markdown | 8 | ||||
| -rw-r--r-- | ruby.html.markdown | 46 |
2 files changed, 50 insertions, 4 deletions
diff --git a/python.html.markdown b/python.html.markdown index 298b7bb7..a32db51a 100644 --- a/python.html.markdown +++ b/python.html.markdown @@ -67,7 +67,7 @@ not False #=> True 2 <= 2 #=> True 2 >= 2 #=> True -# Comparisons can be chained ! +# Comparisons can be chained! 1 < 2 < 3 #=> True 2 < 3 < 2 #=> False @@ -214,7 +214,7 @@ filled_dict.values() #=> [3, 2, 1] "one" in filled_dict #=> True 1 in filled_dict #=> False - # Looking up a non-existing key is a KeyError +# Looking up a non-existing key is a KeyError filled_dict["four"] # KeyError # Use get method to avoid the KeyError @@ -263,7 +263,7 @@ filled_set | other_set #=> {1, 2, 3, 4, 5, 6} some_var = 5 # Here is an if statement. Indentation is significant in python! -# prints "some var is smaller than 10" +# prints "some_var is smaller than 10" if some_var > 10: print "some_var is totally bigger than 10." elif some_var < 10: # This elif clause is optional. @@ -394,7 +394,7 @@ filter(lambda x: x > 5, [3, 4, 5, 6, 7]) #=> [6, 7] # We subclass from object to get a class. class Human(object): - # A class attribute. It is shared by all instances of this class + # A class attribute. It is shared by all instances of this class species = "H. sapiens" # Basic initializer diff --git a/ruby.html.markdown b/ruby.html.markdown index a3bcbbd5..99817982 100644 --- a/ruby.html.markdown +++ b/ruby.html.markdown @@ -325,4 +325,50 @@ dwight.name #=> "Dwight K. Schrute" # Call the class method Human.say("Hi") #=> "Hi" +# Class also is object in ruby. So class can have instance variables. +# Class variable is shared among the class and all of its descendants. + +# base class +class Human + @@foo = 0 + + def self.foo + @@foo + end + + def self.foo=(value) + @@foo = value + end +end + +# derived class +class Worker < Human +end + +Human.foo # 0 +Worker.foo # 0 + +Human.foo = 2 # 2 +Worker.foo # 2 + +# Class instance variable is not shared by the class's descendants. + +class Human + @bar = 0 + + def self.bar + @bar + end + + def self.bar=(value) + @bar = value + end +end + +class Doctor < Human +end + +Human.bar # 0 +Doctor.bar # nil + ``` |