Should I learn XML 1.0 or XML 1.1?

问题:

I know that a well-formed XML 1.1 is not necessarily a well-formed XML 1.0 and vice-versa.

I want to learn xml formally and i was wondering whether i should learn XML 1.0 or XML 1.1? I mean would it be more effective to learn XML 1.0 or would it be more effective to learn XML 1.1?

I mean of course I know its best to read them both.. but i really only have the time to read one of them, so which would be "better" (more useful to me, me as in the average programmer)?

回答1:

Unless you have a specific requirement to work with XML 1.1 (which is very rare), you should read the XML 1.0 Recommendation.

Tim Bray, one of the original editors of the specification, has created an excellent annotated version of it which you can find at:

http://www.xml.com/axml/axml.html

For a bit more info/opinion on XML 1.1, check out what Elliotte Rusty Harold has to say here:

http://www.ibiblio.org/xml/books/effectivexml/chapters/03.html

回答2:

Which is more useful to the average programmer? Neither. The recommendation documents are incredibly dense and difficult to read, in my opinion.

XML is fundamentally pretty simple*, but the documentation makes it look extremely complex. Unless you actually want to implement your own XML stack then skip the recommendation documents and just read the Wikipedia entry, or find a tutorial somewhere that covers the basics.

*Until you start looking at all the extensions. WS-SEC? Ugh.

回答3:

XML 1.0 was first defined in 1998 and went through several (minor) revisions, but was never given a new version number. The latest one came out in 2008, as the 5th edition. "It is widely implemented and still recommended for general use."

XML 1.1 was introduced in 2004 and is currently in its 2nd edition published in 2006. "XML 1.1 is not very widely implemented and is recommended for use only by those who need its unique features."

For more details, see: http://en.wikipedia.org/wiki/XML#Versions

回答4:

The differences between them are very minor. If you are interested in that level of detail, you need to read both. If you aren't interested in that level of detail, you can read either.

回答5:

XML 1.0 is the industry standard and I didn't see any XML 1.1 document yet or any use case, so IMHO much better to learn from W3C XML 1.0 recommendation.