本帖最后由 taroxd 于 2016-4-10 07:15 编辑
Symbol objects represent names and some strings inside the
Ruby interpreter. They are generated using the :name and
:"string" literals syntax, and by the various
to_sym methods. The same Symbol object will be
created for a given name or 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.object_id
$f2.object_id
$f3.object_id
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