Question

So, I got this:

$a = "149.45";
var_dump($a);

gives

string(6) "149.45"

now

$b = $a * 100;
var_dump($b);

so far so good:

float(14945)

and now

$i = (int)$b;
var_dump($i);

What the …?

int(14944)

Tested on PHP 5.2.17 (on CentOS) and PHP 5.3.2-1ubuntu4.9 (On ubuntu).
Can anyone tell me if this is a known bug?
Can anyone test it on a newer PHP version?

EDIT

OK, I got it, float binary representation aproximation error. For my code I already used round().
But why then

$a = 149.45;
$b = 100 * $a;
var_dump($b)
printf('%.10f', $b);

gives

float(14945)
14945.0000000000

? Why that string is not parsed just as 149.45 is parsed?

Answer 1

Illustration of what @Jon said:

$a = "149.45";
$b = $a * 100;
var_dump($b);
printf("%.50f", $b);

result

14944.99999999999818101059645414352416992187500000000000000

“14945” is just a string representation of the above number, not that number itself.