handle view special chars or HTML ASCII in HTML
if string &#lt;
show in HTML <
use javascript-htmlspecialchars
string &#lt;
output in HTML &#lt;
in javascript
var str = '<';
str = util.htmlspecialchars(str);
document.getElementById('area_1').innerHTML= 'innerHTML-' + str;
// jQuery
$('#area_2').html('html-' + str);
$('#area_3').append('append-' + '<span>' + str + '</span>');