[Ruby on Rails] cattr_accessor 與 attr_accessor 差異.

Class 中的 cattr_accessor 與 attr_accessor 初學者常會搞混.
看下面範例就知道啦. 其中 cattr_accessor 產生的變數就是 @@class_count attr_accessor = @instance_count class Counter cattr_accessor :class_count attr_accessor :instance_count end counter1 = Counter.new counter1.instance_count = 1 counter1.class_count = 1 counter2 = Counter.new p counter2.instance_count #> nil p counter2.class_count #> 1