Actionscript 3 and XML

Question

I was wondering how to tell if a "node" of xml contained something. In the below the first two <note> nodes contain a <chord></chord> node but the last one does not how could I check if it contains a node.

<note><chord></chord>
                <pitch><step>C</step>
                    <alter>1</alter>
                    <octave>5</octave>
                </pitch>
                <duration>1</duration>
                <voice>1</voice>
                <type>quarter</type>
                <notations><dynamics><f></f>
                    </dynamics>
                    <technical><string>2</string>
                        <fret>2</fret>
                    </technical>
                </notations>
            </note>
            <note><chord></chord>
                <pitch><step>G</step>
                    <alter>1</alter>
                    <octave>5</octave>
                </pitch>
                <duration>1</duration>
                <voice>1</voice>
                <type>quarter</type>
                <notations><dynamics><f></f>
                    </dynamics>
                    <technical><string>1</string>
                        <fret>4</fret>
                    </technical>
                </notations>
            </note>
            <note><pitch><step>A</step>
                    <octave>5</octave>
                </pitch>
                <duration>1</duration>
                <voice>1</voice>
                <type>quarter</type>
                <notations><dynamics><f></f>
                    </dynamics>
                    <technical><string>1</string>
                        <fret>5</fret>
                    </technical>
                </notations>
            </note>

Answer 1

I got it. I had to check for undefined.

Answer 2

However checking for undefined works. I think you can better check it with the hasOwnProperty() method. With it you can filter your XML a bit more easy. Like so:

// returns the only the nodes which contain "chord"
trace(xml.note.(hasOwnProperty("chord")));

Other ways to implement this (plus some additional XML stuff) can be found over here:

http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/XML.html#hasOwnProperty()