# Json object: convert string to number

**URL:** <https://discourse.nodered.org/t/json-object-convert-string-to-number/38166>\
**Category:** General\
**Created:** [28 December 2020 22:10 UTC](https://discourse.nodered.org/t/json-object-convert-string-to-number/38166 "2020-12-28T22:10:51Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![ueffchen](https://avatars.discourse-cdn.com/v4/letter/u/838e76/32.png) [@ueffchen](https://discourse.nodered.org/u/ueffchen)\
**Post date:** [28 December 2020 22:10 UTC](https://discourse.nodered.org/t/json-object-convert-string-to-number/38166/1 "2020-12-28T22:10:51Z")

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Debug node

> payload.vars.1.value

outputs `string "16"`  
I would like to convert that into a number, but if I use a function with

```auto
msg.payload = new Number(msg.payload.vars.1.value);
return msg;

```

it gives me an error. Any idea why that doesn't work?  
It seems the function cannot fetch the value from the JSON object

Finally I would like a Gauge to display the value

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<div class="post-metadata">

**Author:** ![UnborN](https://avatars.discourse-cdn.com/v4/letter/u/4491bb/32.png) [@UnborN](https://discourse.nodered.org/u/UnborN)\
**Post date:** [28 December 2020 22:16 UTC](https://discourse.nodered.org/t/json-object-convert-string-to-number/38166/2 "2020-12-28T22:16:42Z")

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I think there is an issue accessing number properties of an object with the . (dot) notation  
Try `msg.payload = Number(msg.payload.vars["1"].value)`  
or change the `1` key to something that starts with characters if you have access to how the original payload is constructed.

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<div class="post-metadata">

**Author:** ![ueffchen](https://avatars.discourse-cdn.com/v4/letter/u/838e76/32.png) [@ueffchen](https://discourse.nodered.org/u/ueffchen)\
**Post date:** [28 December 2020 22:22 UTC](https://discourse.nodered.org/t/json-object-convert-string-to-number/38166/3 "2020-12-28T22:22:49Z")

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msg.payload = Number(msg.payload.vars["1"].value)  
or  
msg.payload = Number(msg.payload.vars[1].value)`  
worked, thanks

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [11 January 2021 22:22 UTC](https://discourse.nodered.org/t/json-object-convert-string-to-number/38166/4 "2021-01-11T22:22:53Z")

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