What is Join() in jQuery?

Question

What is Join() in jquery? for example:

var newText = $(\"p\").text().split(\" \").join(\" \"); 

Answer 1

You would probably use your example like this

var newText = "" + $("p").text().split(" ").join(" ") + "";

This will put span tags around all the words in you paragraphs, turning

Test is a demo.

into

Test is a demo.

I do not know what the practical use of this could be.