Ruby: Why does nil.to_s return "", but nil.inspect returns "nil"

Question

Why does nil.to_s return "", but nil.inspect returns "nil" (when apparently .inspect uses the .to_s method)

Answer 1

The "inspect" method of the Object class is supposed to return a human-readable version of the object.

The human-readable version of nil is "nil" and not "" (which is the human readable version of the string "").
That's why nil.inspect should return "nil", whereas nil.to_s returns "" in order for "a string" + nil to return "a string" as it is generally expected (in other languages for instance).