Regex problem

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

Hi monks I have a query see the code snippet below

foreach (@index_corr_file) {
  if ($index == $_) {
    $is_present_flag = 1;
    last;
  }
}
if ($is_present_flag) {
  ##do something
}
[download]

In the above code can i test for the value referred to be $index to be present or not in the array @index_corr_file with in the if condition only. I mean is there a one line answer to the above snippet. Thanks in advance Sid

2005-02-16 Janitored by Arunbear - added code tags, as per Monastery guidelines

Comment on Regex problem Download Code

Replies are listed 'Best First'.
Re: Regex problem by edan (Curate) on Feb 16, 2005 at 11:57 UTC
`perldoc -f grep` -- edan	[reply]
Re: Regex problem by tphyahoo (Vicar) on Feb 16, 2005 at 11:56 UTC
In code tags that would be... `foreach (@index_corr_file) { if ($index == $_) { $is_present_flag = 1; last; } } if ($is_present_flag) { ##do something }` [download] How is this a regex problem though?	[reply] [d/l]
Re: Regex problem by chb (Deacon) on Feb 16, 2005 at 12:01 UTC
I think you are looking for `grep`. See `perldoc -f grep`. Update: not fast enough...	[reply] [d/l] [select]
Re: Regex problem by sh1tn (Priest) on Feb 16, 2005 at 15:16 UTC
Are you sure you do not miss hashes? `@index = qw(1 11 23 45 22); $value = 22; #create hash from array map { $index{$_}++ } @index; #testing for existence exists($index{$value}) and print "yes it does"` [download]	[reply] [d/l]
Re: Regex problem by Anonymous Monk on Feb 16, 2005 at 12:01 UTC
Thank your for your early responses, but my concern here is if the array @index_corr_file has something like qw(1 11 23 45 22) and suppose the $index = 2, then the grep function will be true and the if condition will pass. But i want $index to match to only 2 not otherwise. Is there any way to minimize the code. Sid	[reply]
Re^2: Regex problem by edan (Curate) on Feb 16, 2005 at 12:14 UTC
If you want to test for equality, then by all means! `if ( grep { $index == $_ } @index_corr_file ) { # whatever }` [download] -- edan	[reply] [d/l]
Re^2: Regex problem by prasadbabu (Prior) on Feb 16, 2005 at 12:06 UTC
This will help you, ~~grep(/^$index$/, @index_corr)~~ update: As edan said, it will help you `grep{$index==$_} @index_corr` Prasad	[reply] [d/l]
Re^3: Regex problem by edan (Curate) on Feb 16, 2005 at 12:25 UTC
I downvoted your post, and I'll tell you why - IT'S WRONG! Why would you give somebody a regex solution when they clearly need to test for equality!? What if `$index` contained regex metacharacters? In short, I think it's a bad habit to use an anchored regex when you mean "equals". `perl` provides us with `==` and `eq` for a reason. Use them. -- edan	[reply]