来自专业的译者、企业、网页和免费的翻译库。
if there is already a namespace declaration with the same uri in one of the parent nodes of the node, the prefix of this is taken, otherwise it will take the one provided in the optional parameter prefix or generate a random one.
sets the namespace of a node to uri. if there is already a namespace declaration with the same uri in one of the parent nodes of the node, the prefix of this is taken, otherwise it will take the one provided in the optional parameter prefix or generate a random one.