I am using node-RED to call in data from a robot. In the debug window it says it is a 'msg: Object', and when I copy it to a notepad it takes the format: {"topic":"","payload":27.659992218017578,"_session":{"type":"tcp","id":"0151ff7339437ec6"},"_msgid":"6a6897605a523366"}

I am also not sure if this is a JSON object or not, as I see examples with '' around the brackets.

I am trying to use the function node within node-red to parse this to attain the "payload" value. However, it keeps returning as undefined.

I am using the script:

var json =msg.payload;
var obj = JSON.parse(json);
msg.payload = console.log(obj.payload);
return msg;

I am a beginner to javascript and JSON, however I have tried searching and all examples only have integers as the parsing value. I am also unsure if the value name itself 'payload' is causing an issue. I have also attempted to stringify and using 'getDouble' but had no luck, which I owe to my lack of experience.

I appreciate any guidance.

CodePudding user response：

You don't need to do anything. The value of msg.payload is already a double.

Without a lot more context of what you are trying to do there isn't anything else that we can say here.

CodePudding user response：

After the node that gets the above information (the data in {} in the question}, I then added the 'json' node, and then used the debug node with msg.payload as the output. This output the payload value above as a string. I have now been able to add a function node that allows me to edit the data as needed.