So, from the docs:
2. The optional second parameter (-checked) specifies that the checkbox is turned on by default. Synonyms are -selected and -on.
So, if you omit -checked, the box is unchecked. I'd say this is fairly straightforward, though I would have implemented it with a boolean evaluation myself.
The only way I can find to toggle checked-by-default is to have two seperate statements with logic , one WITH -checked and one without, which is more 2X the syntax I want to use.
Assuming you want a branch, there must be a test in any case. To handle the branching, you could use the ternary Conditional Operator with a list argument: 
print checkbox(-name=>'checkbox_name',
               $checked ? (-checked=>1) : (),
               -value=>'ON',
               -label=>'CLICK ME');

[download]
And, to be fair, weird accumulated crufty behavior is exactly why CGI.pm has been removed from the Perl core.

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

In reply to Re: What's the REAL DEAL with Perl $cgi->checkbox() by kennethk
in thread What's the REAL DEAL with Perl $cgi->checkbox() by misterperl

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