Here are four solutions, starting from the trivial (and arguably most fragile).

use feature 'say';
use DateTime::Format::Strptime qw(strptime strftime);
use Time::Piece;


my $raw_date = '2012-01-12';




# Using tr///; built into Perl.
( my $date = $raw_date ) =~ tr/-//d;
say $date;




# From Time::Piece; core since 5.10.
$date = Time::Piece
  ->strptime( $raw_date, "%Y-%m-%d" )
  ->ymd('');
say $date;




# From DateTime::Format::Strptime; imported functions.
$date = strftime( "%Y%m%d", strptime( "%Y-%m-%d", $raw_date ) );
say $date;




# From DateTime::Format::Strptime; OO interface.
$date = DateTime::Format::Strptime
  ->new( pattern => "%Y-%m-%d" )
  ->parse_datetime($raw_date)
  ->ymd('');
say $date;

[download]

Obviously tr/// is a built-in Perl operator. Time::Piece comes with Perl 5.10 and newer as a core module. DateTime::Format::Strptime is purely a CPAN module that fits into the vast DateTime ecosystem.


Dave

In reply to Re: convert date format from YYYY-MM-DD to YYYYMMDD by davido
in thread convert date format from YYYY-MM-DD to YYYYMMDD by Perlseeker_1

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.