Why uint64, int64 Protobuf-Type be serialize as String JSON-Type in MessageToJsonString()?

[david9991]

Why uint64, int64 Protobuf-Type be serialize as String JSON-Type in MessageToJsonString()?
I tried to use uint64 or int64 to save the Timestamp, and convert it to JSON by MessageToJsonString()
Here is a sample output:

{"timestamp":"1486454809",
"nanosecond":549593000}

that timestamp is int64 or uint64 and nanosecond is int32 Protobuf-Type. Why a 64-bits integer be serialized as String type? Is there any JsonOptions was discussed to support 64-bits integer to JSON integer conversion?

[thomasvl]

That's the spec for the protobuf json format: https://developers.google.com/protocol-buffers/docs/proto3#json

Someone will have to confirm, but I believe the reason is in javascript, some browser can't handle a full 64bit value as a number, so the only way to ensure they can work for those clients is to handle them as strings.

[david9991]

@thomasvl Oh I see, this is a Javascript precision problem that mentioned in some article, thank you very much.