help with float numbers in php

[satish.mumbai]

Hello everyone,

 

Here's something that seems very simple, but has been bothering me for the past few hours !

 

The following code in php

$a = 62745.15;
$b = 64293.6;
$c = 1548.45;
$d = $b - $a - $c;
var_dump($a);
var_dump($b);
var_dump($c);
var_dump($d);

 

gives the following output :

 

float(62745.15)

float(64293.60)

float(1548.45)

float(-2.955857780762E-12)

 

 

My questions :

1. Why does the value of $d not simply come to "float(0)" ??

2. What can I do to get the value of "float(0)" for the calculation as shown in the code above ?

 

Thanks in advance for all your replies.

 

regards,

Satish.

 

[PFMaBiSmAd]

Please read the big pink WARNING at this link - http://www.php.net/manual/en/language.types.float.php

[satish.mumbai]

Hi,

 

Thanks for your reply.... I did read that warning... but somehow i could not make much of it.... can you help me please ?

 

what other options to I have for this kind of calculation ?

 

thanks,

Satish.

[PFMaBiSmAd]

That warning contains a link to BC math functions that don't suffer from floating point conversion errors (because the numbers are operated on as BCD digits.)

[satish.mumbai]

Hi,

 

Thanks again for your reply....

 

unfortunately, the server i am working on does not have BCMath enabled. 

could you suggest any other workaround to this problem ?

 

thanks,

Satish.