Permalink
Browse files

instance method example for clarification

  • Loading branch information...
1 parent 4c42df5 commit b2bcb002bd880d6cea078c693cd9f59cdad2fb2c @ScotterC ScotterC committed Sep 13, 2012
Showing with 20 additions and 0 deletions.
  1. +20 −0 chapters/classes_and_objects/class-methods-and-instance-methods.md
@@ -9,6 +9,7 @@ You want to create a class methods and instance methods.
## Solution
+### Class Method
{% highlight coffeescript %}
class Songs
@_titles: 0 # Although it's directly accessible, the leading _ defines it by convention as private property.
@@ -30,6 +31,25 @@ song.get_count()
# => TypeError: Object #<Songs> has no method 'get_count'
{% endhighlight %}
+### Instance Method
+class Songs
+ _titles: 0 # Although it's directly accessible, the leading _ defines it by convention as private property.
+
+ get_count: ->
+ @_titles
+
+ constructor: (@artist, @title) ->
+ @_titles++
+
+song = new Songs("Rick Astley", "Never Gonna Give You Up")
+song.get_count()
+# => 1
+
+Songs.get_count()
+# => TypeError: Object function Songs(artist, title) ... has no method 'get_count'
+{% endhighlight %}
+
+
## Discussion
Coffeescript will store class methods (also called static methods) on the object itself rather than on the object prototype (and thus on individual object instances), which conserves memory and gives a central location to store class-level values.

0 comments on commit b2bcb00

Please sign in to comment.