given the following code:
vars = instance_variables.map(&method(:instance_variable_get))
vars.each {|v| v = 123}
would that set @something = 123?
taking it a step further
is it the same if i have
vars = instance_variables.map(&method(:instance_variable_get))
vars.each {|v| doSomething(v) }
def doSomething(var)
var = 123
end
how would i mutate var from inside a function?
You can test this in irb pretty quickly:
@something = 456
instance_variables
# => [:@something]
instance_variables.map(&method(:instance_variable_get)).each { |v| v = 123 }
@something
# => 456 (i.e. "didn't mutate @something")
def doSomething(var)
var = 123
end
vars = instance_variables.map(&method(:instance_variable_get))
vars.each { |v| doSomething(v) }
@something
# => 456 (i.e. "didn't mutate @something")
Object#instance_variable_set, however, does change the value of @something:
@something = 456
instance_variables.each { |v| instance_variable_set(v, 123) }
@something
# => 123
v in that last snippet is a symbol: :@something
object_id of the referenced object.Agreeing with pje, you probably should have tested this in irb, but I'm assuming you want to capture a setter for every instance variable, so I'd recommend something like:
setters = instance_variables.map{|v| lambda { |val| instance_variable_set(v, val) }}
then you can just do setters[0].call(__VALUE__) and it will set the value accordingly.
What is it you are trying to achieve?
