How to remove all line breaks from a string

I have a text in a textarea and I read it out using the .value attribute.

Now I would like to remove all linebreaks (the character that is produced when you press Enter) from my text now using .replace with a regular expression, but how do I indicate a linebreak in a regex?

If that is not possible, is there another way?

How you’d find a line break varies between operating system encodings. Windows would be \r\n, but Linux just uses \n and Apple uses \r.

I found this in JavaScript line breaks:

someText = someText.replace(/(\r\n|\n|\r)/gm, "");

That should remove all kinds of line breaks.