Convert a string to a double - is this possible?

Question

Just wondering in php, if it was possible to convert a string to a double. I am using a financial web service which provides a price as a string. I really need to process th

Answer 1

Just use floatval().

E.g.:

$var = '122.34343';
$float_value_of_var = floatval($var);
echo $float_value_of_var; // 122.34343

And in case you wonder doubleval() is just an alias for floatval().

And as the other say, in a financial application, float values are critical as these are not precise enough. E.g. adding two floats could result in something like 12.30000000001 and this error could propagate.

Answer 2

Why is floatval the best option for financial comparison data? bc functions only accurately turn strings into real numbers.

Answer 3

For arbitrary precision mathematics PHP offers the Binary Calculator which supports numbers of any size and precision, represented as strings.

$s = '1234.13';
$double = bcadd($s,'0',2);

PHP: bcadd

Answer 4

Use doubleval(). But be very careful about using decimals in financial transactions, and validate that user input very carefully.