Doing exact real number arithmetic with PHP
Wha开发者_如何学编程t is fastest and most easy way of making basic arithmetic operations on strings representing real numbers in PHP? I have a string representing MySQL's DECIMAL value on which I want to operate and return the result to a database after that. I would like to avoid errors introduced by floating-point real number representation.
Is there some standard library like Python's decimal? Are there any FOSS libraries you can recommend?
Regards
You could use the BC math functions:
http://www.php.net/manual/en/ref.bc.php
Or the GMP functions, although they seem to be integer only.
http://www.php.net/manual/en/ref.gmp.php
You can use the bc_math
extension, which works exactly how you ask (it's used for arbitrary precision numbers):
$num = '123.456';
$twoNum = bcadd($num, $num);
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