# Convert string to number

**URL:** <https://discourse.nodered.org/t/convert-string-to-number/90213>\
**Category:** General\
**Created:** [16 August 2024 10:17 UTC](https://discourse.nodered.org/t/convert-string-to-number/90213 "2024-08-16T10:17:04Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![Sirhc](https://avatars.discourse-cdn.com/v4/letter/s/b77776/32.png) [@Sirhc](https://discourse.nodered.org/u/Sirhc)\
**Post date:** [16 August 2024 10:17 UTC](https://discourse.nodered.org/t/convert-string-to-number/90213/1 "2024-08-16T10:17:04Z")

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Hello

I have a payload which is a string that looks like this "{"id":100,"percent":22.5}". I need to get the 22.5 and convert it to a number, but not sure how to do this? The percent value can go from 0 to 100 (in this case 22.5)

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**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [16 August 2024 10:19 UTC](https://discourse.nodered.org/t/convert-string-to-number/90213/2 "2024-08-16T10:19:28Z")

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> [@Sirhc](#):
>
> I have a payload which is a string that looks like this "{"id":100,"percent":22.5}"

That is JSON. Where did it come from?

TLDR.  
when a value is JSON, it can (SHOULD) be converted to an object so that you can simply get the property using dot notation. e.g. `msg.payload.percent`

As for how to access values, see the part about "copy path" in the below canned text.

  

There’s a great page in the docs ([Working with messages : Node-RED](https://nodered.org/docs/user-guide/messages)) that will explain how to use the debug panel to find the right path/value for any data item.

Pay particular attention to the part about the buttons that appear under your mouse pointer when you over hover a debug message property in the sidebar.

![BX00Cy7yHi](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/b/d/bd1f333a9e043b061b39917c328b0094d3e52d30.gif)

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<div class="post-metadata">

**Author:** ![Sirhc](https://avatars.discourse-cdn.com/v4/letter/s/b77776/32.png) [@Sirhc](https://discourse.nodered.org/u/Sirhc)\
**Post date:** [16 August 2024 10:21 UTC](https://discourse.nodered.org/t/convert-string-to-number/90213/3 "2024-08-16T10:21:06Z")

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All good - thanks - I have converted it correctly now

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<div class="post-metadata">

**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [16 August 2024 10:22 UTC](https://discourse.nodered.org/t/convert-string-to-number/90213/4 "2024-08-16T10:22:22Z")

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> [@Sirhc](#):
>
> Thanks for the response, but the payload is generated by a sensor. I have no control as to what it looks like

Sure you do!

How does the value arrive?

Show us a screenshot of the debug message

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<div class="post-metadata">

**Author:** ![Sirhc](https://avatars.discourse-cdn.com/v4/letter/s/b77776/32.png) [@Sirhc](https://discourse.nodered.org/u/Sirhc)\
**Post date:** [16 August 2024 10:41 UTC](https://discourse.nodered.org/t/convert-string-to-number/90213/5 "2024-08-16T10:41:12Z")

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All good - I corrected my original post - thanks for the help

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<div class="post-metadata">

**Author:** ![jbudd](https://avatars.discourse-cdn.com/v4/letter/j/5f8ce5/32.png) [@jbudd](https://discourse.nodered.org/u/jbudd)\
**Post date:** [16 August 2024 13:10 UTC](https://discourse.nodered.org/t/convert-string-to-number/90213/6 "2024-08-16T13:10:41Z")

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> [@Sirhc](#):
>
> All good - thanks - I have converted it correctly now

There are various ways to get data into Node-red, examples are Serial and MQTT. With some at least of these imports, you can specify that the data is in Json format not a string.  
If your system allows this, it's a better option than "converting" the data, either with a function node or a Json parser node.

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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:** [14 November 2024 13:10 UTC](https://discourse.nodered.org/t/convert-string-to-number/90213/7 "2024-11-14T13:10:44Z")

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