// document.body.innerText;
$('body').text();

//document.body.innerHTML;
$('body').html();

$('body').text(); // innertext
$('body').html();//innerhtml

<div class="demo">Demonstration Box</div>

The code $('.demo').text() would produce the following result:

Demonstration Box

<div class="demo"><p>Demonstration Box</p></div>

$("input").html("text"); will change the---^^^^^^^^^^^^^^^^^---to text