Hello I am reaading one information MQTT in msg.payload. But i receive one string How i can convert it to number ? My intent is show this number in one graph or chart Thank you

The Node-RED Function node uses JavaScript. A quick google search for how to do that will reveal lots of answers, for example: [image] Converting strings to numbers with vanilla JavaScript In JavaScript, you can represent a number is an actual number (ex. 42), or as a string (ex. '42'). I…

though the ui_chart node should cope with a number like string just fine…

remember if you are looking what comes out of an MQTT in node, if you will get a JSON string if the published message was an object. So adding a debug node to the output of the MATT in node will show you the msg type and you can see if you need/want to run it thru a ‘JSON’ node before using it (this…

Hello As you can see, the values comming from topic Umidade (MQTT) I see as string [Picture] I need to convert to number, because the chart does not change

Have you tried parseInt() ... [image] parseInt() The parseInt() function parses a string argument and returns an integer of the specified radix (the base in mathematical numeral systems). ... or parseFloat() ... [image] parseFloat() The parseFloat(…

I am surprised that the gauge node will not work with a string, but to convert it you can use a function node containing msg.payload = Number(msg.payload); return msg;

Me too, will look at that. (Though to be fair the original question did say chart :slight_smile:

Sending strings to Gauge node works fine for me [{"id":"ba62ae94.76cd78","type":"ui_gauge","z":"6dc690a3.1abc88","name":"","group":"88342af7.aabb3","order":0,"width":0,"height":0,"gtype":"gage","title":"Gauge","label":"units","format":"{{value}}","min":0,"max":"100","colors":["#00b500","#e6e600","#…

Indeed - simple strings do seem to work on latest.

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String to number

General

cymplecy 21 June 2018 16:13 3

Or you can use a Change node and a bit of JSONata
e.g string "1234" to 1234

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String to number

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