# Behavior of proc { || } on 1.9

**URL:** <https://www.ruby-forum.com/t/behavior-of-proc-on-1-9/105256>\
**Category:** Ruby\
**Created:** [May 28, 2007, 6:00am UTC](https://www.ruby-forum.com/t/behavior-of-proc-on-1-9/105256 "2007-05-28T06:00:28Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![paulbutcher](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/a5b964/32.png) [@paulbutcher](https://www.ruby-forum.com/u/paulbutcher)\
**Post date:** [May 28, 2007, 6:00am UTC](https://www.ruby-forum.com/t/behavior-of-proc-on-1-9/105256/1 "2007-05-28T06:00:28Z")

</div>

Is this expected behavior?

cout@bean:~$ ruby -v -e ‘proc { || }.call 42’  
ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-linux]  
-e:1: wrong number of arguments (1 for 0) (ArgumentError)  
from -e:1:in `call’  
from -e:1  
cout@bean:~$ ruby1.9 -v -e ‘proc { || }.call 42’  
ruby 1.9.0 (2007-05-26 patchlevel 0) [i686-linux]

---

<div class="post-metadata">

**Author:** ![paulbutcher](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/a5b964/32.png) [@paulbutcher](https://www.ruby-forum.com/u/paulbutcher)\
**Post date:** [May 28, 2007, 1:01pm UTC](https://www.ruby-forum.com/t/behavior-of-proc-on-1-9/105256/2 "2007-05-28T13:01:01Z")

</div>

On May 27, 8:59 pm, Paul B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Is this expected behavior?
> 
> cout@bean:~$ ruby -v -e ‘proc { || }.call 42’  
> ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-linux]  
> -e:1: wrong number of arguments (1 for 0) (ArgumentError)  
> from -e:1:in `call’  
> from -e:1  
> cout@bean:~$ ruby1.9 -v -e ‘proc { || }.call 42’  
> ruby 1.9.0 (2007-05-26 patchlevel 0) [i686-linux]

1.9 gives no such error?  
Seems as 1.8.6 is right on, yet on my system, under 1.8.5 (patchlevel  
35):

irb(main):001:0\> Proc.new{|a| p a}.call 69,70  
(irb):9: warning: multiple values for a block parameter (2 for 1)  
from (irb):9  
[69, 70]  
=\> nil  
irb(main):002:0\> Proc.new{|a,b| p a}.call 69,70,71  
69  
=\> nil

Considering b isnt optional, i.e. specified as “\*b” (where b[1] ==  
71)  
Shouldn’t this raise a 3 for 2 warning?

irb(main):003:0\> def what(a,b)  
irb(main):004:1\> p a  
irb(main):005:1\> p b  
irb(main):006:1\> end  
=\> nil  
irb(main):007:0\> what(1,2,3)  
ArgumentError: wrong number of arguments (3 for 2)  
from (irb):5:in `what’  
from (irb):5  
from :0

I understand that there are differences between a function definition  
and a Proc object, but why are there differences in the way they treat  
their arguments?

---

<div class="post-metadata">

**Author:** ![paulbutcher](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/a5b964/32.png) [@paulbutcher](https://www.ruby-forum.com/u/paulbutcher)\
**Post date:** [May 28, 2007, 3:07pm UTC](https://www.ruby-forum.com/t/behavior-of-proc-on-1-9/105256/3 "2007-05-28T15:07:21Z")

</div>

On 5/27/07, Paul B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Is this expected behavior?
> 
> cout@bean:~$ ruby -v -e ‘proc { || }.call 42’  
> ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-linux]  
> -e:1: wrong number of arguments (1 for 0) (ArgumentError)  
> from -e:1:in `call’  
> from -e:1  
> cout@bean:~$ ruby1.9 -v -e ‘proc { || }.call 42’  
> ruby 1.9.0 (2007-05-26 patchlevel 0) [i686-linux]

In 1.9 proc behaves more like Proc.new IIRC.

Brian.