用regex删除PHP中的某些字符串部分

Question

I am trying to remove certain parts of my string using preg_match. I do not know if this is the best scenario.

I have the following string:

Uploaded Today 13:11, Size 117.09 MiB, ULed by demonoidt

I want to get only the 117.09 part of the string. I am using preg_match like this:

$res = preg_replace("/[^0-9]/", "", $string);

But this will return all the numbers found in the string, so I would have something like:

131111709

Any help would be greatly appreciated. Thank you and happy holidays.

Answer 1

You should be using a matching approach rather than the replacing one.

Use

/([\d.]+)\s*MiB/

Or, if the Size word is always before the number, then use

/Size\s*([\d.]+)/

and grab Group 1 value. See the regex demo (or this demo).

Pattern details:

• ([\d.]+) - Group 1 capturing 1 or more digits or .
• \s* - 0+ whitespaces
• MiB - a sequence of literal chars.

NOTE that you may make the number matching part more precise by replacing [\d.]+ with \d*\.?\d+.

PHP demo:

$re = '/([\d.]+)\s*MiB/';
$str = 'Uploaded Today 13:11, Size 117.09 MiB, ULed by demonoidt';
if (preg_match($re, $str, $match)) {
  echo $match[1]; // => 117.09
}