javascript - jQuery differences in append(string/ref_jquery_obj/jquery_obj)

Question

These are all ways to append a div to the body of the HTML. But what are the differences and when should I use which (performance-wise).

var div = '<div id="divid"></div>';
$('body').append(div);

and

var div = $('<div id="divid"></div>');
$('body').append(div);

and

$div = $('<div id="divid"></div>');
$('body').append($div);

Answer 1

var div = '<div id="divid"></div>';
$('body').append(div);

当您只想将 html 字符串附加到 DOM 时，上面的代码可以正常工作

当您只想将 jQuery 对象附加到 DOM 并且可以使用 jQuery 操作它时，下面的代码可以正常工作

var div = $('<div id="divid"></div>');
div.css({//your css code});//this is not possible in above example
$('body').append(div);