JavaScript automatically converts some special characters

Question

I need to extract a HTML-Substring with JS which is position dependent. I store special characters HTML-encoded.

For example:

HTML

<div id="test"><p>l&ouml;sen &amp; gr&uuml;&szlig;en</p></div>​

Text

lösen & grüßen

My problem lies in the JS-part, for example when I try to extract the fragment lö, which has the HTML-dependent starting position of 3 and the end position of 9 inside the <div> block. JS seems to convert some special characters internally so that the count from 3 to 9 is wrongly interpreted as "lösen " and not "lö". Other special characters like the & are not affected by this.

So my question is, if someone knows why JS is behaving in that way? Characters like ä or ö are being converted while characters like & or   are plain. Is there any possibility to avoid this conversion?

I've set up a fiddle to demonstrate this: JSFiddle

Thanks for any help!

EDIT:

Maybe I've explained it a bit confusing, sorry for that. What I want is the HTML:

<p>l&ouml;sen &amp; gr&uuml;&szlig;en</p> .

Every special character should be unconverted, except the HTML-Tags. Like in the HTML above.

But JS converts the ö or ü into ö or ü automatically, what I need to avoid.

Answer 1

That's because the browser (and not JavaScript) turns entities that don't need to be escaped in HTML into their respective Unicode characters (e.g. it skips &, < and >).

So by the time you inspect .innerHTML, it no longer contains exactly what was in the original page source; you could reverse this process, but it involves the full map of character <-> entity pairs which is just not practical.