regex - replace multi line breaks with single in javascript

Question

this is some kind of variable content in javascript:

    <meta charset="utf-8">      <title>Some Meep meta, awesome</title>         <-- some comment here -->     <meta name="someMeta, yay" content="meep">  </head> 

I want to reduce the multi line breaks (unknown number) to a single line break while the rest of the formatting is still maintained. This should be done in javascript with a regex.

I have problems with the tabulator or to keep the format.

Answer 1

Try this:

text.replace(/\n\s*\n/g, '\n'); 

This basically looks for two line breaks with only whitespace in between. And then it replaces those by a single line break. Due to the global flag g, this is repeated for every possible match.

edit:

is it possibile to leave a double line break instead of a single

Sure, simplest way would be to just look for three line breaks and replace them by two:

text.replace(/\n\s*\n\s*\n/g, '\n\n'); 

If you want to maintain the whitespace on one of the lines (for whatever reason), you could also do it like this:

text.replace(/(\n\s*?\n)\s*\n/, '$1');