Posted by Jared Williams on 03/30/05 01:27

> > I need to output a Hex value, e.g.:
> >
> > 686E8AF8
> >
> > In the following format:
> >
> > 68 6E 8A F8
> >
> > In other words, separated by spaces. Now I realize there
> are a million
> > ways to do this, but I would like a suggestion on which you
> think is
> > the most efficient? Incidentally, I'm starting with a decimal value
> > (23602210718), so maybe sprintf would be a direct way?
>
> sprintf and "most efficient" rarely belong in the same sentence. :-)
>
> I believe this is going to "win" almost any efficiency test,
> and is reasonably self-documenting/clear:
>
> $dec = 23602210718;
> $hex = dechex($dec);
> echo implode(' ', chunk_split($hex, 2));

I presume you meant str_split()

And I think sprintf() is the way togo, it maybe slow, bit it'll be quicker than creating arrays, and rejoining.
Not that either method will make a huge difference unless your doing thousands of such operations.

echo sprintf('%02x %02x %02x %02x', ($dec >> 24) & 0xff, ($dec >> 16) & 0xff, ($dec >> 8) & 0xff, $dec & 0xff);

Jared

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