CSS & Regex, switching values of padding or margin property

问题

I have CSS code where I want to find Padding -or- Margin Properties (where it has 4 values) and to switch the left value with right value:
e.g. padding: 1px 2px 3px 4px;
- to be like this -
padding: 1px 4px 3px 2px;
How can I achieve this with regex & PHP? :-)

回答1:

Try this:

preg_replace(
    '/padding:\s*?(\d*px)\s*(\d*px)\s*(\d*px)\s*(\d*px)\s*?;/i',
    'padding: $1 $4 $3 $2;',
    $css
);

Explanation

\s matches a space

\d matches a digit

\d*px will match any digits followed by a 'px'

来源：https://stackoverflow.com/questions/13191473/css-regex-switching-values-of-padding-or-margin-property