获取从XML到JavaScript的变量值。纯粹的方式

I have XML:

我有XML:

<point>
    ...
    <longitude>34.123123</longitude>
</point>
<point>
    ...
    <longitude>11.12534534</longitude>
</point>
<point>
    ...
    <longitude>32.567653</longitude>
</point>
<point>
    ...
    <longitude>33.345345</longitude>
</point>
...
<point>
    ...
    <lo