如何在Go中将字节数组附加到字节片上[重复]

I have a simple bit of code that i am trying to understand, but am struggling to work out how to get it to work properly.

The general idea is i want to pass some data, and convert it into a byte array. Then i want to apply the length of the byte array at the first index of my byte slice, then add the byte array to end of the slice.

This is what it tried:

    var slice []byte
    myString := "Hello there"

    stringAsByteArray := []byte(myString) //convert my string to byte array


    slice[0] = byte(len(stringAsByteArray)) //length of string as byte array

    append(slice, stringAsByteArray) 

So the idea is the first byte of slice contains the number of len(b) then following on from that, the actual string message as a series of bytes.

But i get:

cannot use stringAsByteArray (type []byte) as type byte in append
append(slice, stringAsByteArray) evaluated but not used

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For example,

package main

import "fmt"

func main() {
    myString := "Hello there"
    slice := make([]byte, 1, 1+len(myString))
    slice[0] = byte(len(myString))
    slice = append(slice, myString...)
    fmt.Println(slice[0], string(slice[1:]))
}

Output:

11 Hello there

1. First of all you need to initialize slice with make function
2. To add data to slice you should use append function
3. To add elements from []byte to []byte you can use spread operator in append call.
4. And finally you need to use result of calling append function

https://play.golang.org/p/CP18akKsCa