如何在XML文档中包含＆符号（＆）？

Question

如何在保持XML有效的同时将&符号放入XML标记的属性中？

<?xml version="1.0" ?> 
<a text="b&c"/> 

当我使用W3School's validator，我得到的错误：

EntityRef: expecting ' ; '

Answer 1

使用字符引用来表示它：&

见specification：

The ampersand character (&) and the left angle bracket (<) MUST NOT appear in their literal form, except when used as markup delimiters, or within a comment, a processing instruction, or a CDATA section. If they are needed elsewhere, they MUST be escaped using either numeric character references or the strings " & " and " < " respectively. The right angle bracket (>) may be represented using the string " > ", and MUST, for compatibility, be escaped using either " > " or a character reference when it appears in the string " ]]> " in content, when that string is not marking the end of a CDATA section.