Does anyone knows how an XML code is complied, since we define of own tags?

Answer 1

you mean like this?


Tove
Jani
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go here to learn more

http://www.w3schools.com/xml/default.asp

Answer 2

XML is a meta language, something being "meta" means it had only few rules to follow, in XML's case:

1. tags are $gt; and $lt; and must match with / closing in pairs or / at the end of name in standalone cases.
2. there are some fixed escape code such as the greater/less than above and quotation marks and so on.
3. nesting must proper just as math parenthis must be proper in their use.
4. only one root tagging pair; since XML editors show the docs as a tree, in fully closed form the GUI should show only one tag.
5. two levels of compliance: well-formed and valid; the first follow the above rules the second has the additional requirement of following some particular semantic definition with structure of tags.

I may have left something out.