Question

I find it surprising that Ruby symbols can be typecasted to integers without errors.
So :a.to_i is legal. I was wondering what is the significance of this integer, is it a unique value specific to that symbol?

Answer 1

You shouldn’t do this, as Symbol#to_i was removed in Ruby 1.9 and is thus not compatible going forward. Regardless, the docs say this about it:

Returns an integer that is unique for each symbol within a particular execution of a program.

It is roughly equivalent to calling object_id on the symbol, as they both end up calling the C function SYM2ID().