如何将父元素的属性设置为子元素的属性?

未测试,但应大致与此相似:

var c = $('#child');
c.attr('title',c.parent().attr('title'));

一步一步地:

var $myElement = $('myElementSelector');      // get your element
var attrValue = $myElement.attr('someAttr');  // get the value of element's attribute
var $parent = $myElement.parent();            // get the element's parent element
$parent.attr('someAttr', attrValue);          // set parent's attribute to child's value 

最后三行可以更简洁地表达:

$myElement.parent().attr('someAttribute', $myElement.attr('someAttribute'););