正则表达式：在起始分隔符和可选的结束分隔符之间捕获

Question

With the following string:

foo/:something/bar/:somethingelse

How can I capture something and somethingelse considering the optional / ending delimiter on the second case?

Using (?<=:)(.*?)(?=\\/) only returns something , which makes sense.

So I've tried (?<=:)(.*?)(?=\\/|$) but it doesn't return somethingelse either.

According to Regex101 this (?=\\/|$) means either / or end of the string, so in principle somethingelse should be captured.

https://regex101.com/r/gU4uR9/2

What am I missing?

Answer 1

As already pointed out by others, the JavaScript regex engine is somewhat crippled (and does not support lookbehinds).
The usual work-around is to match the things before (this consumes characters) and capture the desired substring in a group afterwards:

\/:([^/]+)

See a demo on regex101.com .

In JS code, this would be:

var str = "foo/:something/bar/:somethingelse";
var re = /\/:([^/]+)/g;
var matches = str.match(re);

Thanks to @Wiktor for the clarification of nomenclature.