Cloud Functions：如何获取特定 json 属性的值？

Question

我在发布的 pubsub 消息的消息框中输入的 json 文件如下所示：

{
"message": "Good morning",
"sender": "Joe Schmoe"
}

我尝试通过以下不成功的方式访问“sender”的值：

console.log(decodedJson); //gives decoded json file

console.log("pubsubMessage.sender",pubsubMessage.sender); //returns undefined

console.log("decodedJson.sender",decodedJson.sender); //returns undefined

console.log("decodedJson['sender']",decodedJson["sender"]); //returns undefined

console.log("Decoded Json referencing using object.keys: The", 
Object.keys(decodedJson)[1], " is ", decodedJson[Object.keys(decodedJson)[1]]); //returns "The 1 is "

console.log("pubsubMessage referencing using object.keys: The", Object.keys(pubsubMessage)[1], " is ", pubsubMessage[Object.keys(pubsubMessage)[1]]); //returns "The 1 is w"

console.log("event.after.data().sender ",event.after.data().sender); //returns an error message

供参考，pubsubMessage和decodedJson这两个变量定义如下：

const pubsubMessage = event.data;
const decodedJson=Buffer.from(pubsubMessage, 'base64').toString();

非常感谢您在展示我访问特定属性值的方式方面提供的任何帮助！提前致谢！

Answer 1

以下代码应该可以工作：

exports.pubSubFn = (event, context) => {
  const pubsubMessage = event.data;
  parsed = JSON.parse(Buffer.from(pubsubMessage, 'base64').toString());
  console.log("Sender:" + parsed.sender);
};