问题描述：

How can I replace the text, for example: c2stackoverflow to

span style=\"color:#ffdc50\">stackoverflow</span>\'

I try to do this:

<?php
$string = \"c2stackoverflow\";    
$string = preg_replace(\"/c2([A-Za-záàâãéèêíïóôõöúçñÁÀÂÃÉÈÍÏÓÔÕÖÚÇÑ ])+$/\", \'<span style=\"color:#ffdc50\">$1</span>\', $string);    
echo $string;

But the output is:

<span style=\"color:#ffdc50\">w</span>

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感谢您的意见，我们尽快改进~

功能建议

如何替换文本，例如：c2stackoverflow to </ p>

< code> span style =“color：#ffdc50”＆gt; stackoverflow＆lt; / span＆gt;\'</ code> </ p>

我尝试这样做：</ p>

 ＆lt;？php 
$ string =“c2stackoverflow”;  
$ string = preg_replace（“/ c2（[A-Za-záàâãéèêíïóôõöúçñÁÀÂÃÉÈÍÏÓÔÕÖÚÇÑ]）+ $ /”，\'＆lt; span style =“color：＃ffdc50”＆gt; $ 1＆lt; / span＆gt;\'，$ string）;  
echo $ string; 
</ code> </ pre> 
但输出为：</ p> 
 ＆lt; span style =“color：＃  ffdc50“＆gt; w＆lt; / span＆gt; 
</ code> </ pre> 
</ div> 
网友观点：
Since your original regex shows (by its final $) that you want to replace the entire remainging set of characters after c2, you may simply use this:
$string = preg_replace(\\\"/c2(.*)$/\\\", \'<span style=\\\"color:#ffdc50\\\">$1</span>\', $string);
Note that I replaced + by * so even a string like c2 will be replaced by <span style=\\\"color:#ffdc50\\\"></span>.
    
Just replace plus symbol like this:
$string = preg_replace(\\\"/c2([A-Za-záàâãéèêíïóôõöúçñÁÀÂÃÉÈÍÏÓÔÕÖÚÇÑ ]+)$/\\\", \'<span style=\\\"color:#ffdc50\\\">$1</span>\', $string);
    
请教大神，用正则表达式，将标点符号替换成空格？
把-替换成空格不需要正则表达式。