New subject: [ruby-talk:444086] Re: A simple question about arguments

18 Dec 2022

...
  def tt (x=123)
   puts x
 end => :tt

...
  tt 123
=> nil

...
  tt(456) 456
=> nil

The code above is the default argument I know.

But this one,

...
  def tt2 (x:123)
   puts x 1> end
=> :tt2

...
  tt2 123
=> nil

...
  tt2(456) Traceback (most recent call last):
        5: from /usr/bin/irb:23:in `<main>'
        4: from /usr/bin/irb:23:in `load'
        3: from /Library/Ruby/Gems/2.6.0/gems/irb-1.0.0/exe/irb:11:in `<top
(required)>'
        2: from (irb):10
        1: from (irb):6:in `tt2'
ArgumentError (wrong number of arguments (given 1, expected 0))

As you see it fails.
But the following calling could work.

...
  tt2(x:456) 456
=> nil

...
  tt2(:x=>456) 456
=> nil

what's the trick behind it?

Thanks & regards,
Henry

[ruby-talk:444085] Re: A simple question about arguments