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I am using mongo_dart. Some field contains the Int64 type. I tried to convert the Map<String, dynamic> type that receive from MongoDB to the JSON by using the jsonEncode function but I got this error:

Converting object to an encodable object failed: Instance of 'Int64'

How to fix this?

Should I change the field type to String?

Should I create a function that converts every element in the Map<String, dynamic> from Int64 to Int?

Sittiphan Sittisak
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1 Answers1

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JSON is based on JavaScript, and JavaScript numbers are IEEE-754 double-precision floating-point numbers (doubles), which have a 53-bit significand. They cannot store all 64-bit integers without loss of precision. (JSON implementations can vary in how numbers are stored, but if you care about interoperability, then you should assume doubles as the lowest common denominator.)

Therefore, if you use the full range of 64-bit integers, you're better off storing 64-bit integers as strings.

If 53-bits are sufficient for you, or if you don't care about interoperability and your JSON values will be read and written only by Dart VM code (not Dart for the Web), then you can use ints everywhere and not bother with Int64.

jamesdlin
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