In Ruby, I can define a method foo=(bar):
irb(main):001:0> def foo=(bar)
irb(main):002:1> p "foo=#{bar}"
irb(main):003:1> end
=> nil
Now I'd like to check if it has been defined,
irb(main):004:0> defined?(foo=)
SyntaxError: compile error
(irb):4: syntax error, unexpected ')'
from (irb):4
from :0
What is the proper syntax to use here? I assume there must be a way to escape "foo=" such that it is parsed and passed correctly to the defined? operator.
Best Answer
The problem is that the
foo=
method is designed to be used in assignments. You can usedefined?
in the following way to see what's going on:Compare that to:
To test if the
foo=
method is defined, you should userespond_to?
instead: