I want to convert a hex string to a signed integer Value in Go. My input value is "FF60" and I want the output to be "-160". When I use the following function, the result is "65376", which represents the unsigned representation.
value, err := strconv.ParseInt("FF60", 16, 64)
I would have expected the outcome of 65376 when using the ParseUInt function. Any help would be really appreciated.
The third parameter of strconv.ParseInt() tells the bitsize of the integer you want to parse. 0xff60 parsed as a 64-bit integer is indeed 65376.
You actually want to parse it as a 16-bit integer, so pass 16 as the bitsize. Doing so you will get an error though:
strconv.ParseInt: parsing "FF60": value out of range
Which is true: 0xFF60 (which is 65376) is outside of the valid range of int16 (valid int16 range is [-32768..32767]).
So what you may do is parse it as an unsigned 16-bit integer using strconv.ParseUint(), then convert the result to a signed 16-bit integer:
value, err := strconv.ParseUint("FF60", 16, 16)
fmt.Println(value, err)
fmt.Println(int16(value))
This will output (try it on the Go Playground):
65376 <nil>
-160