In code mode, text with $$ cannot be replaced.

[ChrisYuan1]

[josdejong]

You an use $$$$add as replacement text. Apparently the $ character needs to be escaped in the search box of Ace editor. It may be some feature to replace a pattern or so, but I couldn't find any documentation about that.

[Davidliu11]

Hi @josdejong @ChrisYuan1, I am not sure if this need to be fixed for the Ace-editor, but I think I found root cause for this issue.

See the code above in the Ace editor repo. the replacement string will be handled like the red line marked.
In the case of this issue the replacement is "$$xxxxx", from the doc in MDN the '$$' is a special replacement pattern.

Then after the 'replace', the replacement string will be something '$xxxx'.

[josdejong]

Ahhh, wow, so it is actually a feature that originates in JavaScript's String.prototype.replace(). That explains it. Thanks for figuring this up.

I think we can indeed argue that Ace should fix this, since when the search text is a string (and not a regexp), the $ sign can't be applicable. Ace editor could escape $ signs by escaping them as $$.

[Davidliu11]

@josdejong The Ace-editor guy said they would add fix for this issue. ajaxorg/ace#5486

[josdejong]

That is good news! Thanks for opening the issue at Ace.