Question

just curious why I cann’t remove declared local variable from ‘local_variables’ array.

Example:

x=1
myarr = local_variables.clone
p local_variables
=> [:x, :_]
p myarr
=> [:x, :_]
p local_variables.class
=> Array
p myarr.class
=> Array
myarr.delete :x
p myarr
=> [:_]
local_variables.delete :x
p local_variables
=> [:x, :_]

WTF ?

I did suspected calling local_variables.delete with parameter 😡 reinserts it back as it is declared anew. But if called with other previously undeclared symbol does not change it:

p local_variables
=> [:x, :_]
local_variables.delete :whatever
p local_variables
=> [:x, :_]

Can somebody explain ?

Thx.

Answer 1

Consider the following method:

def foo
  [42, 23, 13]
end

foo #=> [42, 23, 13]
foo.delete 23
foo #=> [42, 23, 13]

Does that behaviour surprise you?

Every time you call local_variables (or foo) a new array is created. If you modify that new array that has no effect on what will happen if you call local_variables again.