Javascript：替换干草堆中不位于两个字符之间的needle

Question

I'd like to replace a needle in a haystack that is not between two characters.

So say I have a regular expression that is /\\bneedle\\b/g , that will match all needle's that are not next to any word character. I want to expand on this and include needle's that are not next to any word character, and NOT between two characters such as [ and ]

So the first three needles will match but the rest will not: needle: needle's needle [needle] [needle something] needle1 needler

Any idea how I'd go about doing this?

Answer 1

You can use this regex:

/(^|[^\w\[])(needle)(?![\w\]])/

RegEx Demo

Breakup:

(^|[^\w\[])    # line start OR a non-word non-[ character
(needle)       # match and group our targeted text
(?![\w\]])     # negative lookahead to fail the match if next char is word char or [

---

As per comments below you can use following replace code:

var str = "needle: needle's needle [needle] [needle something] needle1 needler";
var reg = new RegExp("(^|[^\\w\\[])(needle)(?![\\w\\]])", "gi");
str = str.replace(reg, "$1*$2*");

//=> *needle*: *needle*'s *needle* [needle] [needle something] needle1 needler