jQuery.attr ('class') 和 jQuery.attr ('className') 的区别

<div id="div1" class='A B C D'></div>

$('#div1').attr('class','E F G H');
//二者是一样的
$('#div1').attr('className','E F G H');

document.getElementById('div1').className='E F G H' //正常
document.getElementById('div1').class='E F G H' //失败

jQuery.props = {
"for": "htmlFor",
"class": "className",
readonly: "readOnly",
maxlength: "maxLength",
cellspacing: "cellSpacing",
rowspan: "rowSpan",
colspan: "colSpan",
tabindex: "tabIndex",
usemap: "useMap",
frameborder: "frameBorder"
};

name = notxml && jQuery.props[ name ] || name;