Comparing floats - same number, but does not equal? [duplicate]

Answer 1

Floating point numbers are NOT 100% accurate! You calculation in PHP may return 10.00000000001 which is NOT equal to 10.

Use sprintf ( http://php.net/manual/en/function.sprintf.php ) to format the floats before you compare them.

Answer 2

floating point numbers have limited precision. view the warning about comparing them here:

http://php.net/manual/en/language.types.float.php

Answer 3

Instead of multiplying by one use number_format.

 $carttotal = number_format((int)$carttotal,2,'.','');
 $_REQUEST['amount'] = number_format((int)$_REQUEST['amount'],2,'.','');