正则表达式匹配最后一个字符和字符串

Question

I have a URL that looks as follows...

/images/home/img/digits.png

I need to use regex or some equivalent to get 'digits' from the URL. I am using regex because the same code will be duplicated and the file names will always be different lengths.

I've tried using regex and I get everything after the first / and before the .png, but I need everything after the last / and and before the .png.

Here is what I've been trying:

(?<=/)(.*)(?=.png)

Answer 1

"/images/home/img/digits.png".match(/\/([^\/]*)\.png/i)

回报

["/digits.png", "digits"]

Answer 2

You're really close. (?<=/)([^/]*)(?=\\.png$) should work.

The three things I added do the following:

1. [^/]* matches any character(s) that don't include '/' , so the match can't inlcude any slashes.
2. The \\ before the .png stops the . from matching any character.
3. The $ anchors it to the end of the string.

Also, if you're only looking to match the digits part and you don't care about the rest, you don't need the brackets around [^/]* because the lookahead and lookbehind quantifiers you're using aren't included in the match. So in the above pattern, the only thing that will be returned will be what's matched by [^/]* . This will either be found in the implicit group 0, or in Match.Value if you're using .NET.

To summarise all of that, what I would use is (?<=/)[^/]*(?=\\.png$) . It would also pay to add a case-insensitive flag if you want to also match "/images/home/img/digits.PNG" .