使用JS设置HTML“title”属性不会呈现＆

Question

What is the proper way to use an ampersand in the title attribute? I would have assumed that you should use & , but it gives different behavior depending on whether it was set in the original HTML or modified with JS.

Tooltip rendering in Chrome (Version 47.0.2526.106 (64-bit)) and Safari (Version 9.0.2 (11601.3.9)):

https://jsfiddle.net/davegaeddert/femm9b96/

Answer 1

& means & in HTML .

& means & when you are directly manipulating the DOM using a DOM API.

If you aren't writing HTML, don't use HTML entities.

Answer 2

The method is different depending on how you set it. In raw HTML, you have to escape the ampersand, and your fiddle is doing it correctly:

title="&"

In JavaScript, you can just use "&" in a string:

jQuery("#with-js").attr("title","&");

Answer 3

That's because setAttribute does not parse attributes as HTML. See the specification for Node.setAttribute

When directly in the HTML, it will be parsed for HTML entities

Excerpt

This value is a simple string; it is not parsed as it is being set. So any markup (such as syntax to be recognized as an entity reference) is treated as literal text

https://www.w3.org/TR/DOM-Level-2-Core/core.html#ID-F68F082