问题
Can anyone explain the difference between accessing an instance attribute via self.attribute
and by @attribute
?
回答1:
self.attribute
calls the method attribute
.self.attribute = value
calls the method attribute=
with the argument value
.@attribute
and @attribute = value
get/set the value of the instance variable @attribute
.
So basically they're two entirely different things.
However if you call attr_accessor :attribute
it defines the method attribute
to return @attribute
and the method attribute=(value)
to set @attribute = value
. So in that case, there is no difference.
回答2:
"Accessing instance variable directly is about two times faster than accessing them with accessor methods"
Check out the: http://greyblake.com/blog/2012/09/02/ruby-perfomance-tricks/
来源:https://stackoverflow.com/questions/4639271/directly-accessing-an-instance-variable-vs-using-an-accessor-method