Numeric JSON results in step function are delivered as strings

Question

When using GetQueueAttributes (SQS) to retrieve the number of messages available in a queue, the resulting JSON delivers numbers as strings, e.g. "ApproximateNumberOfMessages": "18"

That means a Choice step can't do a numeric comparison. I know in this particular case I'm always going to get a number, so I can use StringGreaterThan etc., but it's semantically wrong.

How can I convert the string value to a number so I can use numeric comparison operators?

Answer

You need to go step further and learn how comparison is done. It's done by functions Numeric Equals or StringEquals, so your input will be interpreted by the function you choose.

Answer

Use the [States.StringToJson function](https://docs.aws.amazon.com/step-functions/latest/dg/amazon-states-language-intrinsic-functions.html#asl-intrsc-func-json-manipulate) to convert string to number
```
"NumberValue.$": "States.StringToJson("$.numberAsString")"
```

Numeric JSON results in step function are delivered as strings

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