Excuse me for this basic question but, I couldn't find the answer on Google. I am new to Ruby and came across to this line of code:
self.primary_keys = :role_id, :action_name
What I understand from it is that self.primary_keys
is a Class variable and is assigned an array or hash of symbols? What means the right side of the expression ( :role_id, :action_name
)? What is the type of it?
It's two symbols separated by a comma, and is an implicit array.
Equivalent to
self.primary_keys = [:role_id, :action_name]
It's more common to see the technique used on the left side of an assignment.
name, age = ["George", 21]
puts name
=> "George"
puts age
=> 21
The feature lets you swap the contents of variables without an intermediate variable.
For example, in some languages to swap a
and b
you need a temporary variable
temporary = a
a = b
b = temporary
In Ruby you can do
a, b = b, a
It's assignment
x, y = ["Srini", 25]
puts x => "Srini"
puts y => 25
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