如何访问父节点和子节点同名的xml子节点属性

Question

这里我试图通过dom解析访问美元汇率值，但由于孩子的名字和父节点相同，我仍然感到困惑。我请求你帮我解决。

<Cube>
    <Cube time="20:01:33">
        <Cube currency="USD" rate="1.3037"/>
        <Cube currency="JPY" rate="129"/>
        <Cube currency="BGN" rate="1.9558"/>
        <Cube currency="CZK" rate="25.980"/>
        <Cube currency="DKK" rate="7.4591"/>
        <Cube currency="GBP" rate="0.85625"/>
        <Cube currency="HUF" rate="294.07"/>
    </Cube>
</Cube>

WinJS.xhr({ url: "", responseType: "responseXML" }).done(
    function completed(request) {
        var restXML = request.responseXML;
        var element = restXML.documentElement;

        var subElement = element.getElementsByTagName("Cube");
        var dollar = subElement.item(0).attributes[0].name;
        if (dollar == 'USD') {
            var value = subElement.item(1).attributes[1].name;

            currency1.innerText = value;
            // handle completed download.
        }