我的正则表达式没有正确替换

Question

I have this regex: /(?:(?<=(?:style=["])).*)(line-height.*?)[;"]/i

$regex = '/(?:(?<=(?:style=["])).*)(line-height.*?)[;"]/i';

preg_replace("/(?:(?<=(?:style=[\"'])).*)(line-height.*?)[;\"]/i", "HELLO", $input);

This is the input:

    <li><span style="line-height: 20.14399986267089px">500.00dkk</span></li>
<li style="color:red; line-height: 21.14399986267089px"></li>

I want to replace only the occurrences of "line-height: SOMENUMBERpx" with HELLO (It also has to preceded by the style tag): but I can not make it work correctly. Right now it replaces the line-height properties, but it also replace,: color:red, which I do not want.

This is the output I want:

<li><span style=HELLO>500.00dkk</span></li> 
<li style="color:red; HELLO"></li>

Can anyone see what I am doing incorrectly?

Answer 1

You can use \K here.\K resets the starting point of the reported match. Any previously consumed characters are no longer included in the final match

style=.*?\Kline-height.*?(?=[;"])

Try this.See demo.

This will make sure that only line=height... will be replced and it is preceded by style= as well