Question

Given this editable DIV:

<div contenteditable>
    First line
    Second line

    Third line    



    Fourth line
</div>

Live demo: http://jsfiddle.net/Mpvyk/1/

Notice the 3 empty lines between “Third line” and “Fourth line”. I would like to replace those 3 empty lines with a single empty line.

So, inside the DIV, for all occurrences of this:

'\n' (zero or more spaces or tabs) '\n' (zero or more spaces or tabs) '\n' etc.

replace it with one single empty line:

`\n\n`

What I have so far:

var text = div.textContent;

text.replace(/ ??? /gm, '\n\n');

div.textContent = text;

As you can see, I don’t know how to write the regular expression which would select those occurrences of multiple empty lines.

Answer 1

First, I think the regexp you’re after is /\n\s+\n/: a newline, any amount of space-like characters and another newline.

However you’d need to save the result, too: text = text.replace(...).

var div = document.getElementsByTagName('div')[0],
    text = div.textContent;

 text = text.replace(/\n\s+\n/gm, '\n\n');

div.textContent = text;

http://jsfiddle.net/Mpvyk/2/