JavaScript 正则表达式：匹配行并添加新行

Question

I have a problem with a regex expression

I have lines like this:

Line1
Line2
/
Line3
Line4

I'd like to add a new line after each line EXCEPT the lines starting with / Goal:

Line1
#
Line2
#
/
Line3
#
Line4
#

I don't get how to realize this with a single regex call. It always replaces only the first line or 1&3

Answer 1

You can use '/(^[^\\/].*)/gm' as a regex

 const regex = /(^[^\\/].*)/gm; const str = `Line1 Line2 / Line3 Line4`; const subst = `$1\\n`; // The substituted value will be contained in the result variable const result = str.replace(regex, subst); console.log(result);