Re: More math fun

On Tue, 2008-08-12 at 14:59 -0700, Jim Lucas wrote: > Jay Blanchard wrote: > > abs($balanceTest) = 15.22 > > abs($oldLineArray[16]) = 15.22 > > > > $diff = abs($balanceTest) - abs($oldLineArray[16]); > > echo abs($diff) . "\n"; > > > > 1.7763568394E-15 > > > > WTF? This should be a big fat 0 > > > > I do not see how it makes any difference if $balanceTest and $oldLineArray[16] > are strings in the beginning. In line that does the subtraction, they would > have been converted to floats automagically by abs(). If you look at the > manual for this function, you will see that the returned value is either a > float or integer bases on the input type. Float would return a float. > Anything else would return a integer. > > BTW - if I setup the following: > > <?php > > $balanceTest = '15.22'; # A string > $oldLineArray[16] = 15.22; # A float > > $diff = abs($balanceTest) - abs($oldLineArray[16]); > echo abs($diff) . "\n"; > echo gettype(abs($diff)) . "\n"; > > # 1.7763568394E-15 > > ?> > > I get 0 and 'double' Yeah, I was probably thinking abs( $balanceTest - $oldLineArray[16] ) versus what was actually present. But either way, I get 0 doing the above also when I set up the values... so I have no idea how it's not working for Jay. Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP