Parse currency from string

Question

I want to parse a currency from a string in PHP, I've had a look at number formatter but haven't got PHP 5.3 or the ability to add extensions.

The currency will only exist once per string, and will be prefixed with a currency symbol, in my case the pound sign £. The currency may be in one of the following formats:

£0.90
£100
£100.10
£1000

What would be the best method of achieving this?

Edit

Here is an example string:

Paid a bill £153.93

I want to get the currency value into an variable.

Answer 1

(float)substr($input, strpos($input, "£")+1);

This will get you the following results:

float(0.9)
float(100)
float(100.1)
float(1000)
float(153.93)

EDIT: updated to reflect the change to question. this is assuming all strings are like the one you gave as an example.

Answer 2

I've got another answer. Might be a touch faster than using strpos, and would be better if there was any possibility of white space in the input.

$input = "£250.75";
$output = floatval(ltrim($input,"£"));
echo $output;
250.75

You could also add other currencies to the char list in ltrim:

$output = floatval(ltrim($input,"£$¢"));

This would strip $ or £ or ¢ from the left side of your number, as well as white space, which would break the solution above which uses strpos. Also, this would give the same result if the currency symbol was left off in some cases.

Answer 3

preg_match('/(?<=£)(?=[\d.]*\d)(\d*(?:\.\d*)?)/', $input, $matches);

will find a match within any of these:

• £.10
• £0.10
• £100
• £100.00

etc.