.proto Type | Notes | C++ Type | Java/Kotlin Type[1] | Python Type[3] | Go Type | Ruby Type | C# Type | PHP Type | Dart Type |
---|---|---|---|---|---|---|---|---|---|
double | double | double | float | float64 | Float | double | float | double | |
float | float | float | float | float32 | Float | float | float | double | |
int32 | Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint32 instead. | int32 | int | int | int32 | Fixnum or Bignum (as required) | int | integer | int |
int64 | Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint64 instead. | int64 | long | int/long[4] | int64 | Bignum | long | integer/string[6] | Int64 |
uint32 | Uses variable-length encoding. | uint32 | int[2] | int/long[4] | uint32 | Fixnum or Bignum (as required) | uint | integer | int |
uint64 | Uses variable-length encoding. | uint64 | long[2] | int/long[4] | uint64 | Bignum | ulong | integer/string[6] | Int64 |
sint32 | Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int32s. | int32 | int | int | int32 | Fixnum or Bignum (as required) | int | integer | int |
sint64 | Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int64s. | int64 | long | int/long[4] | int64 | Bignum | long | integer/string[6] | Int64 |
fixed32 | Always four bytes. More efficient than uint32 if values are often greater than 228. | uint32 | int[2] | int/long[4] | uint32 | Fixnum or Bignum (as required) | uint | integer | int |
fixed64 | Always eight bytes. More efficient than uint64 if values are often greater than 256. | uint64 | long[2] | int/long[4] | uint64 | Bignum | ulong | integer/string[6] | Int64 |
sfixed32 | Always four bytes. | int32 | int | int | int32 | Fixnum or Bignum (as required) | int | integer | int |
sfixed64 | Always eight bytes. | int64 | long | int/long[4] | int64 | Bignum | long | integer/string[6] | Int64 |
bool | bool | boolean | bool | bool | TrueClass/FalseClass | bool | boolean | bool | |
string | A string must always contain UTF-8 encoded or 7-bit ASCII text, and cannot be longer than 232. | string | String | str/unicode[5] | string | String (UTF-8) | string | string | String |
bytes | May contain any arbitrary sequence of bytes no longer than 232. | string | ByteString | str (Python 2) bytes (Python 3) |
[]byte | String (ASCII-8BIT) | ByteString | string | List |