I have an array of unsigned Integers (from 0 to 255) ```val signerPrivateKey : IntArray = intArrayOf...

# getting-started

[Daniele B]

I have an array of unsigned Integers (from 0 to 255)

val signerPrivateKey : IntArray = intArrayOf(6,199,39,185,82,199,26,124,50,54,50,128,200,204,220,164,48,77,49,31,9,228,77,61,123,53,62,86,163,183,9,172,101,133,107,31,215,181,167,87)

how do I convert it to a ByteArray?

[Paul Griffith]

One way:

val keyAsByte: ByteArray = ByteArray(signerPrivateKey.size) { signerPrivateKey[it].toByte() }

[Francis Mariano]

fun IntArray.toByteArray() : ByteArray {
    val data = mutableListOf<Byte>()
    this.forEach { 
        data.add(it.toByte())
    }
    return data.toByteArray()
}

[Daniele B]

great, thanks!

[Nathan Schwermann]

try something like byteArray.map{it.toByte()}

[Paul Griffith]

map will give you a boxed `List<Byte>`; not critical for the case of a key but a huge performance downgrade compared to sticking with primitives

[ephemient]

do they even need to be in an IntArray in the first place? you can directly get a ByteArray with either of

ubyteArrayOf(6u,199u,39u,185u,82u,199u,26u,124u,50u,54u,50u,128u,200u,204u,220u,164u,48u,77u,49u,31u,9u,228u,77u,61u,123u,53u,62u,86u,163u,183u,9u,172u,101u,133u,107u,31u,215u,181u,167u,87u).toByteArray()
byteArrayOf(6,199.toByte(),39,185.toByte(),82,199.toByte(),26,124,50,54,50,128.toByte(),200.toByte(),204.toByte(),220.toByte(),164.toByte(),48,77,49,31,9,228.toByte(),77,61,123,53,62,86,163.toByte(),183.toByte(),9,172.toByte(),101,133.toByte(),107,31,215.toByte(),181.toByte(),167.toByte(),87)