Swift: How to convert a String to UInt8 array?

Question

How do you convert a String to UInt8 array?

var str = "test" var ar : [UInt8] ar = str 

Answer 1

Lots of different ways, depending on how you want to handle non-ASCII characters.

But the simplest code would be to use the utf8 view:

let string = "hello"  let array: [UInt8] = Array(string.utf8) 

Note, this will result in multi-byte characters being represented as multiple entries in the array, i.e.:

let string = "é" print(Array(string.utf8)) 

prints out [195, 169]

There’s also .nulTerminatedUTF8, which does the same thing, but then adds a nul-character to the end if your plan is to pass this somewhere as a C string (though if you’re doing that, you can probably also use .withCString or just use the implicit conversion for bridged C functions.

Answer 2

let str = "test" let byteArray = [UInt8](str.utf8)