What do you expect $j to be when the callback function gets called?  You have to somehow pass it as an argument to the routine.  There are two ways to pass the value:

Either specify an array(ref) to the -command option 

...
for my $i (0...$#a)
{
    $f->Checkbutton(-text => $a[$i], -command => [ \&fun, $i ] )->pack
+();
}
MainLoop;

sub fun
{
    my $j = shift;
    print $a[$j];
}

[download]

Or use a closure 

...
for my $i (0...$#a)
{
    $f->Checkbutton(-text => $a[$i], -command => sub { fun($i) } )->pa
+ck();
}
...

[download]

In reply to Re: Checkbutton in a loop by Eliya
in thread Checkbutton in a loop by gocpon

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