Generating UUIDs with Swift

Question

I'm trying to generate a UUID using Swift. The official documentation is confusing me a little bit.

The documentation says

init?(uuidString: String) Create a UUID from a string such as “E621E1F8-C36C-495A-93FC-0C247A3E6E5F”.

Does this mean that the string I need to create the UUID from has to be in that format?

For a project I'm doing, I have a string and I want to generate a UUID specifically for that string.

Here's what I tried:

import Foundation

var str = UUID(uuidString: "Hello World")
print(str.uuidString)

This gives me the error,

value of optional type 'UUID?' not unwrapped; did you mean to use '!' or '?'?

I'm still very new to Swift and all this. I don't know what to do in this case.

Basically, I need to generate a UUID SPECIFICALLY for a string (such as "Hello world"), and then I want to use the UUID to return the original string.

Answer 1

UUID().uuidString is used to generate UUIDs. You need to import Foundation to use it.

This is a UUID: E621E1F8-C36C-495A-93FC-0C247A3E6E5F

They are generated from "nothing", they are unique. If you wanted to generate an ID given some string, and generate that same ID at any time using that string, then an UUID will not work for you.

Is it possible you are looking for Base64 encoding?

With Base64, for example, you can encode Hello World as SGVsbG8gV29ybGQ=, and then decode SGVsbG8gV29ybGQ= as Hello World.