javascript multiline regexp replace

Question

"foo\r\nbar".replace(/(foo).+/m, "bar")

Hello. I can not understand why this code does not replace foo on bar

Tomalak · Accepted Answer · 2015-10-30 15:34:10Z

45

I can not understand why this code does not replace foo on bar

Because the dot . explicitly does not match newline characters.

This would work:

"foo\r\nbar".replace(/foo[\s\S]+/m, "bar")

because newline characters count as whitespace (\s).

Note that the parentheses around foo are superfluous, grouping has no benefits here.

answered Apr 4, 2010 at 20:34

Tomalak

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2 Comments

Thanks, I didn't know. In ruby it does by default.

[\s\S] is a much better workaround than (?:.|\s); see Erik Corry's answer to this question for the reason: stackoverflow.com/questions/2407870/…

Kobi · Accepted Answer · 2010-04-04 20:34:48Z

26

JavaScript does not support a dot-all modifier. A common replacement is:

"foo\r\nbar".replace(/(foo)[\s\S]+/, "bar")

/m makes ^ and $ behave correctly, but has not effect on ..

answered Apr 4, 2010 at 20:34

Kobi

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