问题
What would be the easiest regexp selecting all before the 3rd slash
I tried this:
([^\/?#]+){3}(?:.*?\/)
But it does not work exactly as I would hope it would do. Whats more i dont know that it will work in Google Analytics (Filter Section)
回答1:
What you might do instead is ot repeat matching 2 times not a forward slash and then a forward slash.
^(?:[^\/]*\/){2}[^\/]+
See a regex demo
If you don't want to match ?# you could add that to the character class
^(?:[^\/?#]*\/){2}[^\/]+
About your pattern
This part of your pattern ([^\/?#]+){3} captures in a group matching 1+ times any character that is not in the character class but after that repetition takes no forward slash into account.
Then (?:.*?\/) will match any character non greedy followed by a forward slash.
回答2:
In your comment, you give three examples: /, /news/ and /news/details/. Based on these examples, here is a solution:
^(\/[^\/]*){1,2}\/?
It says: from the start of the string match the following:
- a slash, then zero or more non-slashes
- optionally followed by a second slash plus zero or more non-slashes
- optionally followed by a final slash
来源：https://stackoverflow.com/questions/56002107/regexp-select-everything-before-the-3rd-slash