XML Question, I need to know why I should learn it.?

Question

I am a decent programmer, I know

a tad bit of all these languages

Java

C++

Actionscript2.0

HTML

CSS

QBasic

PHP

why should i learn xml?

Answer 1

To be able to continue to develop web sites?  (Like, why learn C++ if you already know C?)

Answer 2

XML is used in many aspects of web development, often to simplify data storage and sharing.

1. XML Separates Data from HTML

2. XML Simplifies Data Sharing

3. XML Simplifies Data Transport

4. XML Simplifies Platform Changes

5. XML Makes Your Data More Available

6. XML is Used to Create New Internet Languages - A lot of new Internet languages are created with XML. Here are some examples:

    * XHTML the latest version of HTML

    * WSDL for describing available web services

    * WAP and WML as markup languages for handheld devices

    * RSS languages for news feeds

    * RDF and OWL for describing resources and ontology

    * SMIL for describing multimedia for the web

Answer 3

XML is used for a lot of different things these days. It's used for data storage, web services, configuration files etc, so it's a good thing to know at least a little bit about it. If you get into any serious amount of development you are bound to bump into some XML.  

Answer 4

XML is becoming the defacto method for data transfer between applications. Since the metatags are part of the content, it helps document the data structure (and, to a degree, the business rules).