That is why this example USES the ref keyword in the correspondence, to express that a mapping should already exist for the referenced element and there is no need to create another one.

这就是本例在通讯中使用关键词ref来表达对引用元素映射应该已经存在而无须再建立一个映射的含义。

youdao

That is why this example USES the ref keyword in the correspondence, to express that a mapping should already exist for the referenced element and there is no need to create another one.

这就是本例在通讯中使用关键词ref来表达对引用元素映射应该已经存在而无须再建立一个映射的含义。

youdao