A Symbol object represents a Ruby name and is generated automatically using the :name literal syntax. The same Symbol object will be created for a given name string for the duration of a program's execution, regardless of the context or meaning of that name. Thus if Fred is a constant in one context, a method in another, and a class in a third, the Symbol :Fred will be the same object in all three contexts.
module One
class Fred
end
$f1 = :Fred
end
module Two
Fred = 1
$f2 = :Fred
end
def Fred()
end
$f3 = :Fred
$f1.id → 2305294
$f2.id → 2305294
$f3.id → 2305294:fred.id2name → "fred":fred.inspect → ":fred"Symbol#id2name.Extracted from the book "Programming Ruby - The Pragmatic Programmer's Guide"
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