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rubyfunctionirb

In Ruby, how to show or print out a function object, without invoking it?

Say, inside of irb if I do

def foo
  return 123
end
foo

it will give 123. That's because Ruby doesn't need the () to invoke the function. But how do I actually print out the function object? (kind of like in the JavaScript console, when I say function foo() {} and type foo, it will show foo as a function (object).)

Solution

  • You can use defined? for that:

    def foo
  return 123
end
foo
#=> 123

defined?(foo)
#=> "method"

    A local variable would return:

    bar = 123
#=> 123

defined?(bar)
#=> "local-variable"

    Or:

    def foo
  return 123
end
foo
#=> 123

method(:foo)
#=> Object#foo()
method(:foo).call
#=> 123