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A quick and easy way to toggle between two values
(This is based on a friend's code, which was based on merlyn's code in a Web Techniques magazine article in January 1999.)
# In the configuration section... my @Toggles = ('on', 'off'); # In some loop in the code... $Toggles[$flip = !$flip]
I use this all the time, usually for background colors:
my @BGColors = ('#dddddd', '#ffffff'); for (1..10){ # As you loop through a database query result or somethin +g print qq{ <tr bgcolor="$BGColors[$flip = !$flip]"> <td>$_</td> </tr> }; }
Voila!

An easily configured, pretty-to-behold alternating background color.

Notes:

  • It's "just" a variable, so it interpolates well (a ternary operator or function call must happen outside quotes, or in @{[ ]} )
  • You can "toggle between" more than 2 values like this:
    • initialize $flip to -1 somewhere before your loop
    • use preincrement and the modulus operator: (see below for full example)
      $Colors[$flip = ++$flip % 4];
# To cycle through any number of elements... my @Cheers = ('hip', 'hip', 'hoo', 'ray'); my $flip = -1; for (1..12){ print "$Cheers[$flip = ++$flip % 4]\n"; }
Enjoy!

Russ


In reply to Flipper by Russ

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