# Converting a JSON String to Object
**URL:** https://discourse.nodered.org/t/converting-a-json-string-to-object/74438
**Category:** General
**Tags:** mqtt
**Created:** [30 January 2023 17:39 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438 "2023-01-30T17:39:05Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@daolio](https://discourse.nodered.org/u/daolio)
#### Post date: [30 January 2023 17:39 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/1 "2023-01-30T17:39:05Z")
So i have a Formated JSON String which is published by a PLC
{"data":{"Temperatura":27,"Umidade":78}}
And i need to convert this string into a Java Script object,
I've tried the JSON parser node as in the image bellow:
But then i got the error:
It may be a simple promblem but i'm really strugling with this.
---
### Author:  [@ghayne](https://discourse.nodered.org/u/ghayne)
#### Post date: [30 January 2023 17:46 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/2 "2023-01-30T17:46:50Z")
Welcome to the forum.
Try setting the MQTT node to return a parsed JSON object and remove the JSON node.
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [30 January 2023 18:10 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/3 "2023-01-30T18:10:23Z")
Strange string length is 41, but error is at position 45. That suggest to me you may have some junk/zero length chars at end of string.
Can you show us a copy value from debug, and maybe a screenshot.
How is the string created and sent to the broker?
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [30 January 2023 18:50 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/4 "2023-01-30T18:50:47Z")
> [@E1cid](#):
>
> Strange string length is 41, but error is at position 45.
That is the length of the error string.
@daolio add a debug node to the mqtt node and show us that.
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [30 January 2023 18:54 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/5 "2023-01-30T18:54:07Z")
Doh!
[edit] Still the string length is only 40 in the supplied example.
---
### Author:  [@daolio](https://discourse.nodered.org/u/daolio)
#### Post date: [30 January 2023 19:42 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/6 "2023-01-30T19:42:37Z")
This is the image from the debug node getting the MQTT Data:
And this is the string beeing published by my PLC:
---
### Author:  [@daolio](https://discourse.nodered.org/u/daolio)
#### Post date: [30 January 2023 19:44 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/7 "2023-01-30T19:44:08Z")
I've tried already but it returns me this error:
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [30 January 2023 19:53 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/8 "2023-01-30T19:53:49Z")
Again data string is 81 but i only count 45.
Can you copy value using debug copy value icon/button (appears when you hover mouse over property name). Post here using \ button.
Something is being added can you expand the orange boxes in image 2.
---
### Author:  [@daolio](https://discourse.nodered.org/u/daolio)
#### Post date: [30 January 2023 19:57 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/9 "2023-01-30T19:57:37Z")
Value : {"data":{"Temperatura":22964,"Umidade":23476}}
And the value on the orange boxes are the same that you see in this table:
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [30 January 2023 20:19 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/10 "2023-01-30T20:19:33Z")
You did not use the \ button when posting as i asked.
Have you tried trimming the string?
e.g.
```auto
[{"id":"d556411065ad6217","type":"inject","z":"da8a6ef0b3c9a5c8","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"data\":{\"Temperatura\":22964,\"Umidade\":23476}}","payloadType":"str","x":150,"y":3980,"wires":[["c6b3048da8f259f9","37ac30dcdea7deb2"]]},{"id":"c6b3048da8f259f9","type":"debug","z":"da8a6ef0b3c9a5c8","name":"debug 226","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":590,"y":3820,"wires":[]},{"id":"37ac30dcdea7deb2","type":"function","z":"da8a6ef0b3c9a5c8","name":"function 20","func":"msg.payload = msg.payload.trim();\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":350,"y":3980,"wires":[["390eff7019b8b578"]]},{"id":"390eff7019b8b578","type":"json","z":"da8a6ef0b3c9a5c8","name":"","property":"payload","action":"","pretty":false,"x":530,"y":3980,"wires":[["c6b3048da8f259f9"]]}]
```
If that works then you definitely have junk chars at end.
---
### Author:  [@daolio](https://discourse.nodered.org/u/daolio)
#### Post date: [30 January 2023 20:23 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/11 "2023-01-30T20:23:24Z")
I got it!
As some of you said the lenght of my string was incorrect, the reason is that i was using the wrong function on my PLC go get the size of the string.
Now that i have the right function, it returns me the size of 45 bytes, wich is correct cause my string has 45 character. Now if i use the JSON parser it creates a JSON Object from my string:
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [13 February 2023 20:23 UTC](https://discourse.nodered.org/t/converting-a-json-string-to-object/74438/12 "2023-02-13T20:23:30Z")
This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.