I'm going crazy - HELP please ??

[gleonard]

In one point in my PHP script a simple compare doesn't seem to be working properly:

echo $newBookingAmountIn;
echo $unpaidAmount;
if ($newBookingAmountIn > $unpaidAmount)
echo "newBookingAmountIn > unpaidAmount";

OUTPUT IS:
28.57
28.57
newBookingAmountIn > unpaidAmount

I thought there might have been a problem with the variables casts. The $newBookingAmountIn is a string and the variable $unpaidAmount is a double so I did the following just to be sure that PHP wasn't having any trouble :

settype($newBookingAmountIn, "double");
settype($unpaidAmount, "double");
echo $newBookingAmountIn."<br>";
echo $unpaidAmount."<br>";;
echo gettype($newBookingAmountIn)."<br>";
echo gettype($unpaidAmount)."<br>";
if ($newBookingAmountIn > $unpaidAmount)
echo "newBookingAmountIn > unpaidAmount";

OUTPUT IS:
28.57
28.57
double
double
newBookingAmountIn > unpaidAmount

In each case the compare results TRUE saying that 28.57 is greater than 28.57.

Any ideas ????

Thanks.

George 🙁

[NogDog]

I would guess it's the result of floating point arithmetic errors. You might want to [man]round()[/man] both values to the desired precision in the comparison, e.g.:

if ( round($newBookingAmountIn, 2) > round($unpaidAmount, 2) )

[Weedpacket]

Even better would be to not use floating-point in the first place: convert 28.57 to 2857, then do your arithmetic and comparisons in integers. Integer arithmetic is faster and doesn't suffer from roundoff errors.

[gleonard]

I tried the round suggestion and it works. Thanks.