# Proc {}.arity is zero

**URL:** <https://www.ruby-forum.com/t/proc-arity-is-zero/137430>\
**Category:** Development\
**Created:** [May 13, 2008, 4:33am UTC](https://www.ruby-forum.com/t/proc-arity-is-zero/137430 "2008-05-13T04:33:57Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [May 13, 2008, 4:33am UTC](https://www.ruby-forum.com/t/proc-arity-is-zero/137430/1 "2008-05-13T04:33:57Z")

</div>

e$B0J2\<$N$h$&$Ke(B proc {}.arity e$B$,e(B 0 e$B$K$J$j$^$9!#e(B

% ./ruby -ve ‘p proc {}.arity’  
ruby 1.9.0 (2008-05-12 revision 16397) [i686-linux]  
0

1.8 e$B$G$Oe(B -1 e$B$G$9!#e(B

% ruby-1.8 -ve ‘p proc {}.arity’  
ruby 1.8.7 (2008-05-07 patchlevel 5000) [i686-linux]  
-1

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [May 13, 2008, 5:37pm UTC](https://www.ruby-forum.com/t/proc-arity-is-zero/137430/2 "2008-05-13T17:37:30Z")

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e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:34669] proc {}.arity is zero”  
on Tue, 13 May 2008 11:33:23 +0900, Tanaka A. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
writes:

|e$B0J2\<$N$h$&$Ke(B proc {}.arity e$B$,e(B 0 e$B$K$J$j$^$9!#e(B  
|  
|% ./ruby -ve ‘p proc {}.arity’  
|ruby 1.9.0 (2008-05-12 revision 16397) [i686-linux]  
|0  
|  
|1.8 e$B$G$Oe(B -1 e$B$G$9!#e(B  
|  
|% ruby-1.8 -ve ‘p proc {}.arity’  
|ruby 1.8.7 (2008-05-07 patchlevel 5000) [i686-linux]  
|-1

1.8e$B$G$Oe(Bproc{}e$B$He(Bproc{||}e$B$O0c$&F0$-$r$9$k$s$G$9$h$M!#e(Bproc{}e$B$Ne(B  
e$BJ}$Oe(Bproc{|\*|}e$B$HF1$8$h$&$KF0:n$7$^$9!#%=!\<%9$r8+$?8B$j$G$O!"e(B  
YARVe$B$O$3$N$U$?$D$r6hJL$9$k\>pJs$r\<N$F$F$k$\_$?$$!#e(B

e$B%Q!\<%6$NJ}$Ge(Bproc{}e$B$re(Bproc{|\*|}e$B$KE83+$9$k$H$$$&J}K!$b$“$j$($k$Ne(B  
e$B$G$9$,!“LLE]$J3d$K$O$”$s$^$j0UL#$,$J$$$h$&$J5$$b$9$k$N$G!”$3e(B  
e$B$l$Oe(B1.9e$B$G$NHs8\_49$JE@$H$$$&$3$H$K$7$?J}$,NI$$$h$&$J5$$,$7$F$-e(B  
e$B$^$7$?!#e(B

---

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [May 14, 2008, 7:10am UTC](https://www.ruby-forum.com/t/proc-arity-is-zero/137430/3 "2008-05-14T07:10:15Z")

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e$B@\>;3OB9-$G$9!#e(B

At Wed, 14 May 2008 00:36:30 +0900,  
Yukihiro M. wrote:

> 1.8e$B$G$Oe(Bproc{}e$B$He(Bproc{||}e$B$O0c$&F0$-$r$9$k$s$G$9$h$M!#e(Bproc{}e$B$Ne(B  
> e$BJ}$Oe(Bproc{|\*|}e$B$HF1$8$h$&$KF0:n$7$^$9!#%=!\<%9$r8+$?8B$j$G$O!"e(B  
> YARVe$B$O$3$N$U$?$D$r6hJL$9$k\>pJs$r\<N$F$F$k$\_$?$$!#e(B

1.8e$B$Ne(Bproc{}e$B$He(Bproc{||}e$B$KBP1~$9$k$N$Oe(B1.9e$B$Ne(Bproc{}e$B$He(Blambda{}e$B$N$h$&$Ke(B  
e$B$\_$($k$N$G!"e(Bproc{}.aritye$B$Oe(B-1e$B$K$J$C$F$[$7$$5$$,$7$^$9!#e(B