why do I receive an empty document [#document: null] when I read a xml file with xmlread?

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Siahlo Ivan 2015-12-19

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评论： Runzhi Jiao 2020-7-11

I tried to read a simple xml file {<rows> <row id='0'> <cell>65</cell> </row> <row id='1'> <cell>565</cell> </row> <row id='2'> <cell>6565</cell> </row></rows>} and received [#document: null].

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Robert Snoeberger 2015-12-19

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编辑：Robert Snoeberger 2015-12-19

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I'm not sure why you think that you received an empty document.

The display that you are seeing, [#document: null], consists of two parts. The first part is #document, which is the node name. When you parse XML with xmlread, you always receive a #document node as the top-level node.

>> dom = xmlread('example.xml')
dom =
[#document: null]
>> getNodeName(dom)
ans =
#document
>>

The second part is null, which is the value of the node. null is used to indicate that the node doesn't have a value.

>> getNodeValue(dom)
ans =
       []
>>

A #text node usually has a value. In your example, the text node under the first cell element has a value of '65'.

>> cells = dom.getElementsByTagName('cell');
>> cell  = cells.item(0)
cell =
[cell: null]
>> text = cell.item(0)
text =
[#text: 65]
>> getNodeValue(text)
ans =
65
>>