One thing to consider about the code: in DOM, the first node represents the document as a whole, so, to get the element book to read the namespaces, you have to go to the children exactly one time.

有关此代码，有一点需要注意：在DOM中，第一个节点代表整个文档，所以，要让元素book读取这些名称空间，必须访问子节点刚好一次。

youdao

One thing to consider about the code: in DOM, the first node represents the document as a whole, so, to get the element book to read the namespaces, you have to go to the children exactly one time.

有关此代码，有一点需要注意：在DOM中，第一个节点代表整个文档，所以，要让元素book读取这些名称空间，必须访问子节点刚好一次。

youdao