在PHP中的字母之间替换分号

Question

I have the following issue, I need to replace all semicolons inside a string which appear only between letters with a slash. The issues is that I also have html entities with semicolons and str_replace messes them up.

Sample string:

Category A > Subcategory A;Category A > Subcategory B;Category B > Subcategory C

Desired output:

Category A > Subcategory A/Category A > Subcategory B/Category B > Subcategory C

Answer 1

To replace semicolon between letter only, you can use regex lookahead and lookbehind.

$str = "Category A > Subcategory A;Category A > Subcategory B;Category B > Subcategory C";
$str = preg_replace("/(?<!\s);(?!\s)/", "/", $str);
echo $str;

or if your html entities is only > then you could use code below

$str = "Category A > Subcategory A;Category A > Subcategory B;Category B > Subcategory C";
$str = preg_replace("/(?<!\&gt);/", "/", $str);
echo $str;