The format is wrong when output int_64 to JSON..

[imkcy9]

When I use MessageToJson function serializing "int64 n" to JSON, the value of n is 40, it should output like {"n":40 }, but the fact is output like {"n":"40"}, how to fix it ??

[trianta2]

I believe this is the line that causes the unexpected output.

This may be a bandaid fix due to a limitation in JavaScript, i.e. it doesn't have support for 64 bit integers, only doubles. Perhaps preserving the original value as a string allows the module to decode it correctly.

[xfxyjwf]

JSON implementations may not support 64-bit integers so to guarantee the value can be round-tripped we print 64-bit integers as strings. If you are consuming the proto JSON output directly, make sure you are doing it in accordance with the proto3 JSON mapping here:

https://developers.google.com/protocol-buffers/docs/proto3#json

Specifically you should accept both numbers and strings for 64-bit proto fields.