现在这不仅仅是另一个What's the difference question，我有done some tests(http://jsfiddle.net/ZC3Lf/)个修改<form action="/test/"></form>​的prop和attr，输出是:

1) prop Modification test
props :http://fiddle.jshell.net/test/1
属性:http://fiddle.jshell.net/test/1

2) Attr Modification test

3) Attr then Prop Modification test
props :http://fiddle.jshell.net/test/11
属性:http://fiddle.jshell.net/test/11

4) Prop then Attr Modification test
Prop: http://fiddle.jshell.net/test/11
Attr: http://fiddle.jshell.net/test/11

Now I am confused about a couple of things, as far as my knowledge goes:
Prop: The value in its current state after any modifications via JavaScript
Attr: The value as it was defined in the html on page load.

Now if this is correct,

• Why does modifying the prop seem to make the action fully qualified, and conversely why does modifying the attribute not?
• 为什么修改1)中的prop会修改属性，这对我来说毫无意义？
• 为什么修改2)中的attr会修改属性，它们是否应该以这种方式链接？

Test Code

HTML

JavaScript

var element = $('form');
var property = 'action';

/*You should not need to modify below this line */

var body = $('body');
var original = element.attr(property);

body.append('<h1>Prop Modification test</h1>');
element.prop(property, element.prop(property) + 1);

body.append('Prop: '+element.prop(property)+'<br />');
body.append('Attr: '+element.attr(property)+'<hr />');

//reset
element.prop(property, original);
element.attr(property, original);

body.append('<h1>Attr Modification test</h1>');
element.attr(property, element.attr(property) + 1);

body.append('Prop: '+element.prop(property)+'<br />');
body.append('Attr: '+element.attr(property)+'<hr />');

//reset
element.prop(property, original);
element.attr(property, original);

body.append('<h1>Attr then Prop Modification test</h1>');
element.attr(property, element.attr(property) + 1);
element.prop(property, element.prop(property) + 1);

body.append('Prop: '+element.prop(property)+'<br />');
body.append('Attr: '+element.attr(property)+'<hr />');

//reset
element.prop(property, original);
element.attr(property, original);

body.append('<h1>Prop then Attr Modification test</h1>');
element.prop(property, element.prop(property) + 1);
element.attr(property, element.attr(property) + 1);

body.append('Prop: '+element.prop(property)+'<br />');
body.append('Attr: '+element.attr(property)+'<hr />');