if statement not working

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks I have a simple perl script

#! /usr/bin/perl

while(<DATA>) {
  chomp($_) ;
  if ( $_ == "aaaa" ) {
    print "$_\n" ;
  }
  else {
    print "OK\n" ;
  }
}

__DATA__
aaaa
bbbb
cccc
dddd
[download]

Running it gives

aaaa
bbbb
cccc
dddd
[download]

I expected

aaaa
OK
OK
OK
[download]

Any help would be appreciated!

Comment on if statement not working Select or Download Code

Replies are listed 'Best First'.
Re: if statement not working by GrandFather (Saint) on Feb 08, 2009 at 09:12 UTC
Always use strictures (use strict; use warnings;)! If you turn strictures on you will get the warning: `Argument "aaaa" isn't numeric in numeric eq (==) at ...` [download] Use the string equality operator (eq) for comparing strings. The numeric equality operator (==) will "numify" its operands and non-numeric strings numify to 0. Perl's payment curve coincides with its learning curve.	[reply] [d/l]
Re: if statement not working by alienmonk (Initiate) on Feb 08, 2009 at 09:42 UTC
Just a small change in your code if ( $_ == "aaaa" ) , you are comparing characters so it should be if ( $_ eq "aaaa" ) Now it should work.	[reply]
Re: if statement not working by Anonymous Monk on Feb 08, 2009 at 09:12 UTC
fixed it, for stings perl uses eq	[reply]
Re: if statement not working by salazar (Scribe) on Feb 08, 2009 at 23:52 UTC
Yeah Perl is different from the other languages I've worked with in that == is type-specific, use `eq - equal to ne - not equal to` [download] for strings, as suggested above.	[reply] [d/l]