Channels ▼

Web Development

Building Your Own Perl Modules

Jan03: Building Your Own Perl Modules, Part I

sub oneof {
 my $item = $_[0];     # The item to search for in the array.
 my $lstr = $_[1];     # List of items in string separated by commas
 my $sepr = $_[2];     # Separator (default is comma)
 # if the separator was not passed, then default to a comma.

 if ($sepr =~ /^$/ || $sepr !~ /.{1}/) { $sepr = ","; }

 # Split the list string into an array for the search.

 @list = split(/$sepr/,$lstr);

 $found = 0;           # Set found to 0 in case item is not found.

 # Search through the items in the list array from first (index = 0)
 # to last (index = number of items in list [ $#list ] - 1)

 for ($x = 0; $x < $#list; $x++) {
   if ($item eq $list[$x]) {
     $found = $x+1;    # Set found to index+1 if item is found.
     last;             # Discontinue for loop if found
 return $found;        # Return value of found to calling script.

Example 1: oneof subroutine with comments.

Related Reading

More Insights

Currently we allow the following HTML tags in comments:

Single tags

These tags can be used alone and don't need an ending tag.

<br> Defines a single line break

<hr> Defines a horizontal line

Matching tags

These require an ending tag - e.g. <i>italic text</i>

<a> Defines an anchor

<b> Defines bold text

<big> Defines big text

<blockquote> Defines a long quotation

<caption> Defines a table caption

<cite> Defines a citation

<code> Defines computer code text

<em> Defines emphasized text

<fieldset> Defines a border around elements in a form

<h1> This is heading 1

<h2> This is heading 2

<h3> This is heading 3

<h4> This is heading 4

<h5> This is heading 5

<h6> This is heading 6

<i> Defines italic text

<p> Defines a paragraph

<pre> Defines preformatted text

<q> Defines a short quotation

<samp> Defines sample computer code text

<small> Defines small text

<span> Defines a section in a document

<s> Defines strikethrough text

<strike> Defines strikethrough text

<strong> Defines strong text

<sub> Defines subscripted text

<sup> Defines superscripted text

<u> Defines underlined text

Dr. Dobb's encourages readers to engage in spirited, healthy debate, including taking us to task. However, Dr. Dobb's moderates all comments posted to our site, and reserves the right to modify or remove any content that it determines to be derogatory, offensive, inflammatory, vulgar, irrelevant/off-topic, racist or obvious marketing or spam. Dr. Dobb's further reserves the right to disable the profile of any commenter participating in said activities.

Disqus Tips To upload an avatar photo, first complete your Disqus profile. | View the list of supported HTML tags you can use to style comments. | Please read our commenting policy.