Question:
What is the difference between these two possibilities?
//com @
@post = Post.find(params[:id])
//sem @
post = Post.find(params[:id])
Normally in controllers it is used with @ , but in each functions of views it is usually used without @ , for example.
Are there any performance differences?
Answer:
variables that have @ are instance variables in the scope of the current object. variables without @ are local variables in the scope of the current object.
In the specific case of Rails, variables with @ used in controllers are made available to be used "inside" views.
For the each that was mentioned, follow the example below:
@posts.each do |post|
<faz alguma coisa com 'post' aqui>
end
in this code snippet, the post variable is local to the scope of the block in which it was defined, so it only exists within do |post| ... end block. do |post| ... end
To better understand the differences between the types of variables, classes and objects, take a look at this link http://aprendaaprogramar.rubyonrails.com.br/index.rb?Chapter=09 .
About each , look here http://aprendaaprogramar.rubyonrails.com.br/index.rb?Chapter=07