string comparison
in [Perl]
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From: Shashank Khanvilkar on 29 Sep 2005 12:36 Hi, I think i am doing something wrong here. Can anyone please let me know what $a = "apple"; if ($a eq ('apple')){ print "right choice\n"; }else{ print "wrong choice\n"; } This above prints "right choice". But the below prints "wrong choice". How can i make the below program print "right choice". $a = "apple"; if ($a eq ('apple'|'banana')){ print "right choice\n"; }else{ print "wrong choice\n"; }
From: Paul Lalli on 29 Sep 2005 13:17 Shashank Khanvilkar wrote: > Hi, > I think i am doing something wrong here. Can anyone please let me know what > > $a = "apple"; > > if ($a eq ('apple')){ Those inner parentheses are unneeded, and serve only to clutter the expression. > print "right choice\n"; > }else{ > print "wrong choice\n"; > } > > This above prints "right choice". But the below prints "wrong choice". > How can i make the below program print "right choice". > > $a = "apple"; > > if ($a eq ('apple'|'banana')){ > print "right choice\n"; > }else{ > print "wrong choice\n"; > } The eq operator tests for equality. The | operator does a bit-wise 'or' on its arguments. Therefore, the string you are testing for equality to eq is: 'cq~moa' ('a' | 'b' = 'c', 'p' | 'a' = 'q', etcetera). I *think* what you're looking for is a regular expression, or pattern match. You want to determine if $a contains either of your two strings: if ($a =~ /apple|banana/) { print "\$a contains either 'apple' or 'banana'\n"; } Read more on regular expressions in a variety of documentation: perldoc perlre perldoc perlretut perldoc perlreref perldoc perlrequick Paul Lalli
From: Gunnar Hjalmarsson on 29 Sep 2005 13:19 Babacio wrote: > Shashank Khanvilkar <shashank(a)mia.ece.uic.edu> writes: >>How can i make the below program print "right choice". >> >>$a = "apple"; >> >>if ($a eq ('apple'|'banana')){ >> print "right choice\n"; >>}else{ >> print "wrong choice\n"; >>} > > But if I guess what you really want to do, try that : > > if ($a eq 'apple' || $a eq 'banana') { etc } or this: if ( grep $a eq $_, ('apple', 'banana') ) { (perldoc -f grep) > And read some documentation, Indeed. -- Gunnar Hjalmarsson Email: http://www.gunnar.cc/cgi-bin/contact.pl
From: Anno Siegel on 30 Sep 2005 07:48 Gunnar Hjalmarsson <noreply(a)gunnar.cc> wrote in comp.lang.perl.misc: > Babacio wrote: > > Shashank Khanvilkar <shashank(a)mia.ece.uic.edu> writes: > >>How can i make the below program print "right choice". > >> > >>$a = "apple"; > >> > >>if ($a eq ('apple'|'banana')){ > >> print "right choice\n"; > >>}else{ > >> print "wrong choice\n"; > >>} > > > > But if I guess what you really want to do, try that : > > > > if ($a eq 'apple' || $a eq 'banana') { etc } > > or this: > > if ( grep $a eq $_, ('apple', 'banana') ) { > > (perldoc -f grep) ....or use Quantum::Superposition Anno -- If you want to post a followup via groups.google.com, don't use the broken "Reply" link at the bottom of the article. Click on "show options" at the top of the article, then click on the "Reply" at the bottom of the article headers.
From: Tassilo v. Parseval on 30 Sep 2005 15:53
Also sprach Anno Siegel: > Gunnar Hjalmarsson <noreply(a)gunnar.cc> wrote in comp.lang.perl.misc: >> Babacio wrote: >> > But if I guess what you really want to do, try that : >> > >> > if ($a eq 'apple' || $a eq 'banana') { etc } >> >> or this: >> >> if ( grep $a eq $_, ('apple', 'banana') ) { >> >> (perldoc -f grep) > > ...or use Quantum::Superposition Yuck. I'd suggest use List::MoreUtils qw/any/; if (any { $a eq $_ } qw/apple banana/) { Tassilo -- use bigint; $n=71423350343770280161397026330337371139054411854220053437565440; $m=-8,;;$_=$n&(0xff)<<$m,,$_>>=$m,,print+chr,,while(($m+=8)<=200); |