# Assigned but unused variable

**URL:** <https://www.ruby-forum.com/t/assigned-but-unused-variable/191876>\
**Category:** Development\
**Created:** [July 20, 2010, 3:17am UTC](https://www.ruby-forum.com/t/assigned-but-unused-variable/191876 "2010-07-20T03:17:22Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![SASADA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f1d935/32.png) [@SASADA\_Koichi](https://www.ruby-forum.com/u/SASADA_Koichi)\
**Post date:** [July 20, 2010, 3:17am UTC](https://www.ruby-forum.com/t/assigned-but-unused-variable/191876/1 "2010-07-20T03:17:22Z")

</div>

e$B!!$5$5$@$G$9!%e(B

e$B!!:G6ae(B ruby -w e$B$GF0$+$9$H;H$o$l$FL5$5$=$&$JJQ?t$KBP$7$Fe(B  
“assigned but  
unused variable” e$B$H7Y9p$7$F$/$l$k$h$&$G$9!%e(B

e$B!!$G!$$$$D$be(B -w  
e$BIU$-$GF0$+$7$F$$$k;d$G$9$,!$I8=`%i%$%V%i%j$G$b$$$/$D$+$3e(B  
e$B$N7Y9p$,=P$F$$$k$h$&$G$9!%BP=hD:$/$H$$$$$H;W$&$N$G$9$,!$$I$&$G$7$g$&$+!%e(B

# e$B8D?ME\*$K$O!$e(Bbenchmark e$B$H$+$h$/;H$&$N$G!$]5F+$7$$!%e(B

e$B!!;29M$^$G$K!$e(Bruby 1.9.3dev (2010-07-19 trunk 28681)  
[i386-mswin32\_90]  
e$B$G0J2\<$N%9%/%j%W%H$r\<B9T$7$F$\_$^$7$?!%e(B

$:.each{|dir|  
(Dir.glob(File.join(dir, ‘_.rb’)) + Dir.glob(File.join(dir,  
'net/_.rb’))).each{|rb|  
next if File.basename(rb) == ‘debug.rb’  
puts rb  
begin  
require rb  
rescue Exception =\> e  
puts “Error: #{e}”  
end  
}  
}

ruby 1.9.3dev (2010-07-19 trunk 28681) [i386-mswin32\_90]  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb:561: warning: assigned but  
unused variable - i  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb:561: warning: assigned but  
unused variable - a  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb:562: warning: assigned but  
unused variable - a  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb:563: warning: assigned but  
unused variable - a  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb:568: warning: assigned but  
unused variable - i  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb:568: warning: assigned but  
unused variable - a  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb:569: warning: assigned but  
unused variable - a  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb:570: warning: assigned but  
unused variable - a  
lib/complex.rb is deprecated  
c:/ruby/trunk/lib/ruby/1.9.1/digest.rb:14: warning: assigned but unused  
variable - e  
c:/ruby/trunk/lib/ruby/1.9.1/rubygems.rb:1062: warning: method  
redefined; discarding old gem  
internal:gem\_prelude:15: warning: previous definition of gem was here  
c:/ruby/trunk/lib/ruby/1.9.1/rubygems/source\_index.rb:360: warning:  
assigned but unused variable - name  
c:/ruby/trunk/lib/ruby/1.9.1/rubygems/specification.rb:674: warning:  
assigned but unused variable - default\_value  
c:/ruby/trunk/lib/ruby/1.9.1/rubygems/specification.rb:706: warning:  
assigned but unused variable - yaml  
c:/ruby/trunk/lib/ruby/1.9.1/rubygems/custom\_require.rb:7: warning:  
loading in progress, circular require considered harmful -  
c:/ruby/trunk/lib/ruby/1.9.1/rubygems.rb  
from t.rb:1:in `<main>' from t.rb:1:in`each’  
from t.rb:2:in `block in <main>' from t.rb:2:in`each’  
from t.rb:6:in `block (2 levels) in <main>' from t.rb:6:in`require’  
from c:/ruby/trunk/lib/ruby/1.9.1/gauntlet\_rubygems.rb:1:in `<top (required)>' from c:/ruby/trunk/lib/ruby/1.9.1/gauntlet_rubygems.rb:1:in`require’  
from c:/ruby/trunk/lib/ruby/1.9.1/rubygems.rb:1119:in `<top (required)>' from c:/ruby/trunk/lib/ruby/1.9.1/rubygems.rb:1119:in`require’  
from c:/ruby/trunk/lib/ruby/1.9.1/rubygems/custom\_require.rb:7:in  
`<top (required)>' from c:/ruby/trunk/lib/ruby/1.9.1/rubygems/custom_require.rb:7:in`require’  
c:/ruby/trunk/lib/ruby/1.9.1/abbrev.rb  
c:/ruby/trunk/lib/ruby/1.9.1/base64.rb  
c:/ruby/trunk/lib/ruby/1.9.1/benchmark.rb  
c:/ruby/trunk/lib/ruby/1.9.1/cgi.rb  
c:/ruby/trunk/lib/ruby/1.9.1/cmath.rb  
c:/ruby/trunk/lib/ruby/1.9.1/complex.rb  
c:/ruby/trunk/lib/ruby/1.9.1/csv.rb  
c:/ruby/trunk/lib/ruby/1.9.1/date.rb  
c:/ruby/trunk/lib/ruby/1.9.1/delegate.rb  
c:/ruby/trunk/lib/ruby/1.9.1/digest.rb  
c:/ruby/trunk/lib/ruby/1.9.1/dl.rb  
c:/ruby/trunk/lib/ruby/1.9.1/drb.rb  
c:/ruby/trunk/lib/ruby/1.9.1/e2mmap.rb  
c:/ruby/trunk/lib/ruby/1.9.1/English.rb  
c:/ruby/trunk/lib/ruby/1.9.1/erb.rb  
c:/ruby/trunk/lib/ruby/1.9.1/fileutils.rb  
c:/ruby/trunk/lib/ruby/1.9.1/find.rb  
c:/ruby/trunk/lib/ruby/1.9.1/forwardable.rb  
c:/ruby/trunk/lib/ruby/1.9.1/gauntlet\_rubygems.rb  
Error: cannot load such file – gauntlet  
c:/ruby/trunk/lib/ruby/1.9.1/getoptlong.rb  
c:/ruby/trunk/lib/ruby/1.9.1/gserver.rb  
c:/ruby/trunk/lib/ruby/1.9.1/ipaddr.rb  
c:/ruby/trunk/lib/ruby/1.9.1/irb.rb  
c:/ruby/trunk/lib/ruby/1.9.1/json.rb  
Error: cannot load such file – iconv  
c:/ruby/trunk/lib/ruby/1.9.1/kconv.rb  
c:/ruby/trunk/lib/ruby/1.9.1/kconv.rb:205: warning: assigned but unused  
variable - form\_enc  
c:/ruby/trunk/lib/ruby/1.9.1/i386-mswin32\_90/nkf.so: warning: failed to  
load encoding (UTF-32BE); use ASCII-8BIT instead  
c:/ruby/trunk/lib/ruby/1.9.1/logger.rb  
c:/ruby/trunk/lib/ruby/1.9.1/mathn.rb  
c:/ruby/trunk/lib/ruby/1.9.1/matrix.rb  
c:/ruby/trunk/lib/ruby/1.9.1/mkmf.rb  
c:/ruby/trunk/lib/ruby/1.9.1/monitor.rb  
c:/ruby/trunk/lib/ruby/1.9.1/mutex\_m.rb  
c:/ruby/trunk/lib/ruby/1.9.1/observer.rb  
c:/ruby/trunk/lib/ruby/1.9.1/open-uri.rb  
c:/ruby/trunk/lib/ruby/1.9.1/open-uri.rb:129: warning: assigned but  
unused variable - perm  
c:/ruby/trunk/lib/ruby/1.9.1/open-uri.rb:483: warning: assigned but  
unused variable - parameters  
c:/ruby/trunk/lib/ruby/1.9.1/open-uri.rb:715: warning: assigned but  
unused variable - v  
c:/ruby/trunk/lib/ruby/1.9.1/uri/common.rb:352: warning: assigned but  
unused variable - uri\_ref  
c:/ruby/trunk/lib/ruby/1.9.1/open3.rb  
c:/ruby/trunk/lib/ruby/1.9.1/optparse.rb  
c:/ruby/trunk/lib/ruby/1.9.1/optparse.rb:1075: warning: assigned but  
unused variable - n  
c:/ruby/trunk/lib/ruby/1.9.1/ostruct.rb  
c:/ruby/trunk/lib/ruby/1.9.1/pathname.rb  
c:/ruby/trunk/lib/ruby/1.9.1/pp.rb  
c:/ruby/trunk/lib/ruby/1.9.1/prettyprint.rb  
c:/ruby/trunk/lib/ruby/1.9.1/prime.rb  
c:/ruby/trunk/lib/ruby/1.9.1/profile.rb  
c:/ruby/trunk/lib/ruby/1.9.1/profiler.rb  
c:/ruby/trunk/lib/ruby/1.9.1/pstore.rb  
c:/ruby/trunk/lib/ruby/1.9.1/rake.rb  
c:/ruby/trunk/lib/ruby/1.9.1/rake.rb:1041: warning: assigned but unused  
variable - ex  
c:/ruby/trunk/lib/ruby/1.9.1/rake.rb:1690: warning: assigned but unused  
variable - arg\_names  
c:/ruby/trunk/lib/ruby/1.9.1/rake.rb:1798: warning: assigned but unused  
variable - md  
c:/ruby/trunk/lib/ruby/1.9.1/rake.rb:2248: warning: assigned but unused  
variable - ex2  
c:/ruby/trunk/lib/ruby/1.9.1/rational.rb  
lib/rational.rb is deprecated  
c:/ruby/trunk/lib/ruby/1.9.1/rdoc.rb  
c:/ruby/trunk/lib/ruby/1.9.1/resolv-replace.rb  
c:/ruby/trunk/lib/ruby/1.9.1/resolv-replace.rb:54: warning: assigned but  
unused variable - err  
c:/ruby/trunk/lib/ruby/1.9.1/dl/import.rb:99: warning: assigned but  
unused variable - prekey  
c:/ruby/trunk/lib/ruby/1.9.1/dl/struct.rb:101: warning: assigned but  
unused variable - size  
c:/ruby/trunk/lib/ruby/1.9.1/win32/resolv.rb:76: warning: character  
class has duplicated range: /^[\w\d]+./  
c:/ruby/trunk/lib/ruby/1.9.1/resolv.rb  
c:/ruby/trunk/lib/ruby/1.9.1/ripper.rb  
c:/ruby/trunk/lib/ruby/1.9.1/rss.rb  
c:/ruby/trunk/lib/ruby/1.9.1/rss/rss.rb:1098: warning: assigned but  
unused variable - model\_uri  
c:/ruby/trunk/lib/ruby/1.9.1/rss/rss.rb:1098: warning: assigned but  
unused variable - getter  
c:/ruby/trunk/lib/ruby/1.9.1/rss/rss.rb:1096: warning: assigned but  
unused variable - \_tags  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/element.rb:877: warning: assigned but  
unused variable - rv  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/element.rb:1095: warning: assigned  
but unused variable - element\_document  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/element.rb:1200: warning: assigned  
but unused variable - res  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/child.rb:91: warning: assigned but  
unused variable - encoding  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/attribute.rb:118: warning: assigned  
but unused variable - doctype  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/doctype.rb:118: warning: assigned but  
unused variable - next\_indent  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/doctype.rb:255: warning: `+’ after  
local variable is interpreted as binary operator  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/doctype.rb:255: warning: even though  
it seems like unary operator  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/functions.rb:173: warning: assigned  
but unused variable - test\_string  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/xpath\_parser.rb:689: warning:  
assigned but unused variable - enum  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/parsers/xpathparser.rb:285: warning:  
assigned but unused variable - res  
c:/ruby/trunk/lib/ruby/1.9.1/rexml/parsers/xpathparser.rb:581: warning:  
assigned but unused variable - arry  
c:/ruby/trunk/lib/ruby/1.9.1/rss/atom.rb:530: warning: assigned but  
unused variable - subtype  
c:/ruby/trunk/lib/ruby/1.9.1/rss/maker/1.0.rb:35: warning: assigned but  
unused variable - set  
c:/ruby/trunk/lib/ruby/1.9.1/rss/maker/0.9.rb:27: warning: assigned but  
unused variable - set  
c:/ruby/trunk/lib/ruby/1.9.1/rss/maker/0.9.rb:260: warning: assigned but  
unused variable - set  
c:/ruby/trunk/lib/ruby/1.9.1/rss/maker/dublincore.rb:17: warning:  
assigned but unused variable - full\_klass\_name  
c:/ruby/trunk/lib/ruby/1.9.1/rubygems.rb  
c:/ruby/trunk/lib/ruby/1.9.1/scanf.rb  
c:/ruby/trunk/lib/ruby/1.9.1/securerandom.rb  
c:/ruby/trunk/lib/ruby/1.9.1/set.rb  
c:/ruby/trunk/lib/ruby/1.9.1/shell.rb  
c:/ruby/trunk/lib/ruby/1.9.1/shell/system-command.rb:87: warning:  
assigned but unused variable - th  
c:/ruby/trunk/lib/ruby/1.9.1/shell/system-command.rb:112: warning:  
assigned but unused variable - th  
c:/ruby/trunk/lib/ruby/1.9.1/sync.rb:131: warning: assigned but unused  
variable - ret  
(eval):7: warning: method redefined; discarding old included  
(eval):7: warning: previous definition of included was here  
c:/ruby/trunk/lib/ruby/1.9.1/shell.rb:49: warning: method redefined;  
discarding old debug=  
c:/ruby/trunk/lib/ruby/1.9.1/shell.rb:115: warning: method redefined;  
discarding old debug=  
c:/ruby/trunk/lib/ruby/1.9.1/shellwords.rb  
c:/ruby/trunk/lib/ruby/1.9.1/singleton.rb  
c:/ruby/trunk/lib/ruby/1.9.1/socket.rb  
c:/ruby/trunk/lib/ruby/1.9.1/syck.rb  
c:/ruby/trunk/lib/ruby/1.9.1/sync.rb  
c:/ruby/trunk/lib/ruby/1.9.1/tempfile.rb  
c:/ruby/trunk/lib/ruby/1.9.1/thread.rb  
c:/ruby/trunk/lib/ruby/1.9.1/thwait.rb  
c:/ruby/trunk/lib/ruby/1.9.1/time.rb  
c:/ruby/trunk/lib/ruby/1.9.1/timeout.rb  
c:/ruby/trunk/lib/ruby/1.9.1/tmpdir.rb  
c:/ruby/trunk/lib/ruby/1.9.1/tracer.rb  
c:/ruby/trunk/lib/ruby/1.9.1/tsort.rb  
c:/ruby/trunk/lib/ruby/1.9.1/ubygems.rb  
c:/ruby/trunk/lib/ruby/1.9.1/un.rb  
c:/ruby/trunk/lib/ruby/1.9.1/uri.rb  
c:/ruby/trunk/lib/ruby/1.9.1/weakref.rb  
c:/ruby/trunk/lib/ruby/1.9.1/webrick.rb  
c:/ruby/trunk/lib/ruby/1.9.1/webrick/log.rb:63: warning: assigned but  
unused variable - str  
c:/ruby/trunk/lib/ruby/1.9.1/webrick/httpresponse.rb:283: warning:  
assigned but unused variable - remain  
c:/ruby/trunk/lib/ruby/1.9.1/webrick/httpservlet/erbhandler.rb:47:  
warning: assigned but unused variable - meta\_vars  
c:/ruby/trunk/lib/ruby/1.9.1/webrick/httpservlet/erbhandler.rb:48:  
warning: assigned but unused variable - query  
c:/ruby/trunk/lib/ruby/1.9.1/Win32API.rb  
Warning:c:/ruby/trunk/lib/ruby/1.9.1/rubygems/custom\_require.rb:31:  
Win32API is deprecated after Ruby 1.9.1; use dl directly instead  
c:/ruby/trunk/lib/ruby/1.9.1/win32ole.rb  
c:/ruby/trunk/lib/ruby/1.9.1/yaml.rb  
c:/ruby/trunk/lib/ruby/1.9.1/net/ftp.rb  
c:/ruby/trunk/lib/ruby/1.9.1/net/ftp.rb:325: warning: assigned but  
unused variable - resp  
c:/ruby/trunk/lib/ruby/1.9.1/net/http.rb  
c:/ruby/trunk/lib/ruby/1.9.1/net/http.rb:1566: warning: assigned but  
unused variable - main  
c:/ruby/trunk/lib/ruby/1.9.1/net/https.rb  
Error: cannot load such file – openssl  
c:/ruby/trunk/lib/ruby/1.9.1/net/imap.rb  
c:/ruby/trunk/lib/ruby/1.9.1/net/imap.rb:2683: warning: assigned but  
unused variable - mailbox  
c:/ruby/trunk/lib/ruby/1.9.1/net/pop.rb  
c:/ruby/trunk/lib/ruby/1.9.1/net/protocol.rb  
c:/ruby/trunk/lib/ruby/1.9.1/net/smtp.rb  
c:/ruby/trunk/lib/ruby/1.9.1/net/telnet.rb  
c:/ruby/trunk/lib/ruby/1.9.1/i386-mswin32\_90/rbconfig.rb

---

<div class="post-metadata">

**Author:** ![SASADA\_Koichi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/f1d935/32.png) [@SASADA\_Koichi](https://www.ruby-forum.com/u/SASADA_Koichi)\
**Post date:** [July 20, 2010, 6:52am UTC](https://www.ruby-forum.com/t/assigned-but-unused-variable/191876/2 "2010-07-20T06:52:45Z")

</div>

e$B@.@%$G$9!#e(B

2010e$BG/e(B7e$B7ne(B20e$BF|e(B10:16 SASADA Koichi [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> e$B:G6ae(B ruby -w e$B$GF0$+$9$H;H$o$l$FL5$5$=$&$JJQ?t$KBP$7$Fe(B “assigned but  
> unused variable” e$B$H7Y9p$7$F$/$l$k$h$&$G$9!%e(B
> 
> e$B$G!$$$$D$be(B -w e$BIU$-$GF0$+$7$F$$$k;d$G$9$,!$I8=`%i%$%V%i%j$G$b$$$/$D$+$3e(B  
> e$B$N7Y9p$,=P$F$$$k$h$&$G$9!%BP=hD:$/$H$$$$$H;W$&$N$G$9$,!$$I$&$G$7$g$&$+!%e(B
> 
> # e$B8D?ME\*$K$O!$e(Bbenchmark e$B$H$+$h$/;H$&$N$G!$]5F+$7$$!%e(B

irb e$B$Ge(B $VERBOSE=true e$B$9$k$H!"e(B  
irb(main):001:0\> a=1  
(irb):1: warning: assigned but unused variable - a  
=\> 1  
e$B$H=P$?$j$7$^$9$M$'e(B