Good day

I am trying to display my weather data in a JSON format in order to use it in an iOS app (using swift in Xcode). This is what my code looks like at the moment:

CloudDeploy[APIFunction[{"location" -> "Location"}, 
{temp : QuantityMagnitude[WeatherData[#location, "Temperature"]], 
hum : QuantityMagnitude[WeatherData[#location, "Humidity"]], 
windD : QuantityMagnitude[WeatherData[#location, "WindDirection"]], 
windS : QuantityMagnitude[WeatherData[#location, "WindSpeed"]]} &,
"JSON"], Permissions -> "Public"] 

This code produces the following output (after you put in "? location=Stellenbosch" at the end of the URL):

Failed to export to JSON for input:
{temp:21.4, hum:0.526, windD:320, windS:11.3} 

But if I change the output to "Text" then it gives the following output (after giving it a location parameter):


How do I get the weather data in a JSON format??

Thank you in advance


1 Answer 1


The : is used for named patterns, it's not part of any key-value data structure in Mathematica. You will not find it used in the way you propose anywhere in the documentation. You could use either a list of rules:

  "key1" -> "value1",
  "key2" -> "value2"
  }, "JSON"]

"{ "key1": "value1", "key2": "value2" }"

Or an Association:

  "key1" -> "value1",
  "key2" -> "value2"
  |>, "JSON"]

"{ "key1": "value1", "key2": "value2" }"

I'm showing here that those data structures can be exported to JSON, you do not need to use ExportString, that's not the point.


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