At 10:18 06.11.2002, Daevid Vincent said:
--------------------[snip]--------------------
>doesn't lend itself nicely to expansion, but may be my only way. I just
>have a gut feeling that it can be automated somehow. To turn 1,3,4 into
>10110 seems like there is some 'math' there that can work. I also
--------------------[snip]--------------------
It's quite easy using the left-shift operator "<<". Note that the function
below only works for values 1-31 on 32bit systems.
<?php
function makebits(&$array)
{
$result = 0;
foreach ($array as $seq) {
if (is_numeric($seq)) {
$i = 1 << ($seq-1); // assuming ID's are 1-based
$result += $i;
}
}
return $result;
}
$a = array(1,3,5,9); // 1 0001 0101 = 0x115
echo '<xmp>', sprintf('0x%x', makebits($a)), "\n</xmp>";
?>
--
>O Ernest E. Vogelsinger
(\) ICQ #13394035
^ http://www.vogelsinger.at/
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