Regex problem

[Anonymous Monk]

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
}

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

[edan]

perldoc -f grep

[tphyahoo]

In code tags that would be...

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

How is this a regex problem though?

[chb]

I think you are looking for grep. See perldoc -f grep.

Update: not fast enough...

[sh1tn]

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"

[Anonymous Monk]

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

[edan]

If you want to test for equality, then by all means!

if ( grep { $index == $_ } @index_corr_file )
{
    # whatever
}

[prasadbabu]

This will help you,

grep(/^$index$/, @index_corr)

update:

As edan said, it will help you

grep{$index==$_} @index_corr

[edan]

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.