# 1.0.div(0.0) vs. 1.0.divmod(0.0)

**URL:** <https://www.ruby-forum.com/t/1-0-div-0-0-vs-1-0-divmod-0-0/137952>\
**Category:** Development\
**Created:** [May 18, 2008, 9:34pm UTC](https://www.ruby-forum.com/t/1-0-div-0-0-vs-1-0-divmod-0-0/137952 "2008-05-18T21:34:56Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Akinori\_MUSHA](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/b782af/32.png) [@Akinori\_MUSHA](https://www.ruby-forum.com/u/Akinori_MUSHA)\
**Post date:** [May 18, 2008, 9:34pm UTC](https://www.ruby-forum.com/t/1-0-div-0-0-vs-1-0-divmod-0-0/137952/1 "2008-05-18T21:34:56Z")

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　div と divmod の以下の挙動の相違は意図されたものでしょうか。

irb(main):001:0\> 1.0.div(0.0)  
FloatDomainError: Infinity  
from (irb):1:in `div' from (irb):1 from /Users/knu/bin/irb-1.9:12:in`’  
irb(main):002:0\> 1.0.divmod(0.0)  
=\> [NaN, NaN]  
irb(main):003:0\> RUBY\_VERSION  
=\> “1.9.0”

　ruby\_1\_8 でも同じですが、 ruby\_1\_8\_6 だと divmod も以下の  
ように例外を上げます。

irb(main):001:0\> 1.0.divmod(0.0)  
-e:1:in `divmod’: NaN (FloatDomainError)  
from -e:1

---

<div class="post-metadata">

**Author:** ![Akinori\_MUSHA](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/b782af/32.png) [@Akinori\_MUSHA](https://www.ruby-forum.com/u/Akinori_MUSHA)\
**Post date:** [May 25, 2008, 1:46am UTC](https://www.ruby-forum.com/t/1-0-div-0-0-vs-1-0-divmod-0-0/137952/2 "2008-05-25T01:46:39Z")

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　この件はどうでしょうか。意図せざるものにも思えますが。

　もしバグなら 1.8.7 までに直したいので、検討をお願いします。

At Mon, 19 May 2008 04:34:29 +0900,

---

<div class="post-metadata">

**Author:** ![Akinori\_MUSHA](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/b782af/32.png) [@Akinori\_MUSHA](https://www.ruby-forum.com/u/Akinori_MUSHA)\
**Post date:** [May 26, 2008, 4:51pm UTC](https://www.ruby-forum.com/t/1-0-div-0-0-vs-1-0-divmod-0-0/137952/3 "2008-05-26T16:51:46Z")

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

In message “Re: [ruby-dev:34740] 1.0.div(0.0) vs. 1.0.divmod(0.0)”  
on Mon, 19 May 2008 04:34:29 +0900, “Akinori MUSHA”  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|e$B!!e(Bdiv e$B$He(B divmod e$B$N0J2\<$N5sF0$NAj0c$O0U?^$5$l$?$b$N$G$7$g$&$+!#e(B  
|  
|irb(main):001:0\> 1.0.div(0.0)  
|FloatDomainError: Infinity  
| from (irb):1:in `div' | from (irb):1 | from /Users/knu/bin/irb-1.9:12:in `’  
|irb(main):002:0\> 1.0.divmod(0.0)  
|=\> [NaN, NaN]  
|irb(main):003:0\> RUBY\_VERSION  
|=\> “1.9.0”

1.9e$B$G$Oe(BFloate$B$N1i;;7k2L$G$“$ke(BInfe$B$de(BNaNe$B$r1#$5$:8+$;$k$h$&$K$7$^e(B  
e$B$7$?!#$N$G!”$3$l$O0U?^$7$?$b$N$G$9!#$,!"e(Bdive$B$O4pK\E\*$K@0=|$G$9e(B  
e$B$+$i!"e(BZeroDivision e$B$G$bNI$$$N$+$b$7$l$^$;$s!#e(B

|e$B!!e(Bruby\_1\_8 e$B$G$bF1$8$G$9$,!"e(B ruby\_1\_8\_6 e$B$@$He(B divmod e$B$b0J2\<$Ne(B  
|e$B$h$&$KNc30$r\>e$2$^$9!#e(B

1.8e$B$G$O;EMM$OJQ$o$i$J$$J}$,$h$$$N$G$O$J$$$G$7$g$&$+!#e(B