Convert an integer to a byte array

Question

I have a function which receives a   byte but I what I have is an int  what is the best way to go about this conversion   err   a Write   byte myInt     I guess I could go the long way and get it into a string and put that into bytes  but it sounds ugly and I guess there are better ways to do it

User · Answer

Adding this option for dealing with basic uint8 to byte[] conversion

foo := 255 // 1 - 255
ufoo := uint16(foo) 
far := []byte{0,0}
binary.LittleEndian.PutUint16(far, ufoo)
bar := int(far[0]) // back to int
fmt.Println("foo, far, bar : ",foo,far,bar)

output : foo, far, bar : 255 [255 0] 255

User · Answer

Sorry  this might be a bit late  But I think I found a better implementation on the go docs   buf    new bytes Buffer  var num uint16   1234 err    binary Write buf  binary LittleEndian  num  if err    nil       fmt Println  binary Write failed    err    fmt Printf    x   buf Bytes

User · Answer

I agree with Brainstorm s approach  assuming that you re passing a machine-friendly binary representation  use the encoding binary library   The OP suggests that binary Write   might have some overhead   Looking at the source for the implementation of Write    I see that it does some runtime decisions for maximum flexibility  func Write w io Writer  order ByteOrder  data interface    error          Fast path for basic types      var b  8 byte     var bs   byte     switch v    data  type        case  int8          bs   b  1          b 0    byte  v      case int8          bs   b  1          b 0    byte v      case  uint8          bs   b  1          b 0     v          Right   Write   takes in a very generic data third argument  and that s imposing some overhead as the Go runtime then is forced into encoding type information   Since Write   is doing some runtime decisions here that you simply don t need in your situation  maybe you can just directly call the encoding functions and see if it performs better  Something like this  package main  import        quot encoding binary quot       quot fmt quot     func main         bs    make   byte  4      binary LittleEndian PutUint32 bs  31415926      fmt Println bs     Let us know how this performs  Otherwise  if you re just trying to get an ASCII representation of the integer  you can get the string representation  probably with strconv Itoa  and cast that string to the   byte type  package main  import        quot fmt quot       quot strconv quot     func main         bs      byte strconv Itoa 31415926       fmt Println bs

User · Answer

Check out the  encoding binary  package  Particularly the Read and Write functions   binary Write a  binary LittleEndian  myInt

User · Answer

What s wrong with converting it to a string     byte fmt Sprintf   d   myint

[go] Convert an integer to a byte array

Examples related to go

Examples related to type-conversion