How to append byte to byte array in golang? Not byte array to byte array slices etc

Question

var a byte
var b []byte
i know how to do this
c := append(b,a...)

but how do i do this elegantly?

c := append(a,b...) <-- what's the solution does anyone knows?

Would like to have the c[0] == a, c[1:] == b for checking next time

You cannot append to arrays in Go. Arrays are fixed-length. But you don't have an array, you have a slice. — Jonathan Hall, Jun 13 '20 at 07:42
Beyond that, what you have is already pretty elegant. What are you hoping to improve? — Jonathan Hall, Jun 13 '20 at 07:52

score 2 · Answer 1 · answered Jun 13 '20 at 03:48

2

You can make a a slice as well then append it with b.

c := append([]byte{a}, b...)

answered Jun 13 '20 at 03:48

gzcz

score 1 · Answer 2 · edited Jun 13 '20 at 07:52

1

You can use the bytes.Buffer to make this cleaner:

var a byte
var buf bytes.Buffer

buf.WriteByte(a)// For a single byte
buf.Write([]byte{a})// For byte slice

edited Jun 13 '20 at 07:52

Jonathan Hall

answered Jun 13 '20 at 04:12

Ashwin Shirva

Why bytes.buffer? is it slower or faster? – Alpha1 Jun 15 '20 at 21:14
It is a handy wrapper around byte slice, and also it implements several interfaces, io.Reader, io.Writer to name a few. It is an ideal choice when you have a lot of values to append, and also it provides methods for efficient conversion of byte slice to string. – Ashwin Shirva Jun 16 '20 at 02:17

2 Answers2