小编Mic*_*ogu的帖子

考虑Firebase快速入门指南中引用的此数据结构(此处)

{"name": {"first": "Fred","last": "Flintstone"}

文档说,可以使用以下命令访问查询返回的"name"的每个子对象的数据快照位置:

var ref = new Firebase("https://docs-examples.firebaseio.com/samplechat/users/fred");
ref.once("value", function(snapshot) {
     var nameSnapshot = snapshot.child("name");
     var name = nameSnapshot.val();

     name === { first: "Fred", last: "Flintstone"}

     var firstNameSnapshot = snapshot.child("name/first");
     var firstName = firstNameSnapshot.val();
     firstName === "Fred"

     var lastNameSnapshot = snapshot.child("name").child("last");
     var lastName = lastNameSnapshot.val();
     lastName === "Flintstone"

     var ageSnapshot = snapshot.child("age");
     var age = ageSnapshot.val();
     age === null (because there is no "age" child in the data snapshot)
});

但是,当处理以下行时,有点奇怪.

var nameSnapshot = snapshot.child("name"); …