jsonpb，为什么要把int64解码成json，结果是字符串。 像 int64 str=10 -->str:"10"

Question

//code:630

//jsonpb, why int64 -> json is string. like 10-->"10"

//https://github.com/golang/protobuf/blob/master/jsonpb/jsonpb.go

// Default handling defers to the encoding/json library.
b, err := json.Marshal(v.Interface())
if err != nil {
    return err
}
needToQuote := string(b[0]) != `"` && (v.Kind() == reflect.Int64 || v.Kind() == reflect.Uint64)
if needToQuote {
    out.write(`"`)
}
out.write(string(b))
if needToQuote {
    out.write(`"`)
}

Question:

Why append "\\'" around the value?

Answer 1

Because way that integers are represented in javascript means that the maximum integer is (2 to the power of 53)-1 (see https://stackoverflow.com/a/307200/1153938 )

The biggest int from an int64 is larger than that, so in order to protect from the case of large ints, the library does a string of digits instead

As javascript numbers are signed the same goes for large negative numbers