Programming Ruby
The Pragmatic Programmer's Guide
class Method
Parent:
Object
Version:
1.6
Index:
[ ]
arity
call
to_proc
Method objects are created by
Object#method
, and are associated
with a particular object (not just with a class). They may be used
to invoke the method within the object, and as a block associated with
an iterator.
class Thing
def square(n)
n*n
end
end
aThing = Thing.new
aMethod = aThing.method("square")
aMethod.call(9)
サ
81
[ 1, 2, 3 ].collect(&aMethod)
サ
[1, 4, 9]
instance methods
[ ]
meth[
[
args
]*
]
->
anObject
Synonym for
Method.call.
arity
meth.arity ->
aFixnum
Returns an indication of the number of arguments accepted by a method.
Returns a nonnegative integer for methods that take a fixed number
of arguments. For Ruby methods that take a variable number of
arguments, returns -n-1, where n is the number of required
arguments. For methods written in C, returns -1 if the call
takes a variable number of arguments.
call
meth.call(
[
args
]*
)
->
anObject
Invokes the
meth with the specified
arguments, returning the method's return value.
m = 12.method("+")
m.call(3)
サ
15
m.call(20)
サ
32
Returns a
Proc object corresponding to this method.
Extracted from the book "Programming Ruby -
The Pragmatic Programmer's Guide"
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2001 by Addison Wesley Longman, Inc. This material may
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