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iOS

Posted by Mike Atkinson
Mike Atkinson
6,882 Points

Further Explanation of Associated Values of Enum

While enums and raw values are ok, I'm having a hard time wrapping my head around associated values. Is the associated value like a property of the member? Is the associated value separate or linked to the member? Why use associated values?

Any help or examples would be appreciated.

1 Answer

Kevin Hamil
Kevin Hamil
8,203 Points
Kevin Hamil
Kevin Hamil
8,203 Points

The Apple docs describe associated values very well. I would suggest reading their explanation to get the full understanding (when in doubt, always check the Apple docs). https://developer.apple.com/library/ios/documentation/swift/conceptual/Swift_Programming_Language/Enumerations.html

Basically, the associated value specifies what the value type of the member should be. In their example, they have...

enum Barcode {
    case UPCA(Int, Int, Int, Int)
    case QRCode(String)
}

...the associated value of UPCA should be 4 Int values, while QRCode is just a single string, but they're both still barcodes and new barcodes added can be added as either type, provided their input matches the associated value format.