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A question in dtd tutorial example


Guest zhangbaodi
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Guest zhangbaodi

I'm reading dtd tutorial,I see an exampleDeclaring mixed content<!ELEMENT note (#PCDATA|to|from|header|message)*>I think it is same as<!ELEMENT note (#PCDATA)*> Is that right ?If not,why

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As far as I'm aware, the things after #PCDATA declare the elements that could only occur once as childs of that element. If you don't include them, then all declared elements could be placed more then once as childs of note. For example, with

<!ELEMENT note (#PCDATA)*><!ELEMENT to	  (#PCDATA)><!ELEMENT from	(#PCDATA)><!ELEMENT heading (#PCDATA)><!ELEMENT body	(#PCDATA)>

the following XMLs are valid:

<note><to>Tove</to><from>Jani</from><body>Don't forget me this weekend!</body></note>

<note><to>Tove</to><to>Hege</to><from>Jani</from><from>Kaijim</from><from>Stale</from><heading>Reminder</heading><body>Don't forget me this weekend!</body><body>Or I'll forget you.</body></note>

Whereas with

<!ELEMENT note (#PCDATA|to|from|header|message)*><!ELEMENT to	  (#PCDATA)><!ELEMENT from	(#PCDATA)><!ELEMENT heading (#PCDATA)><!ELEMENT body	(#PCDATA)>

Only the first example is valid. I'm not sure though.

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hey!this<!ELEMENT note (#PCDATA|to|from|header|message)*>declares that the element "note" can have either character data or element to or element from or header or message.this example means that since note can contain any no. of character data or element "to" or element "from" or "header" or "message".

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hey!this<!ELEMENT note (#PCDATA|to|from|header|message)*>declares that the element "note" can have either character data...
Don't you mean "Parsable Character data", which btw practically means "any well formed XML data".
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