In Swift enumerations, what’s the difference between raw values and associated values?
Answer Posted / iosraj
Raw values are used to associate constant (literal) values to enum cases. The value type is part of the enum type, and each enum case must specify a unique raw value (duplicate values are not allowed).
The following example shows an enum with raw values of type Int:
enum IntEnum : Int {
case ONE = 1
case TWO = 2
case THREE = 3
}
An enum value can be converted to its raw value by using the rawValue property:
var enumVar: IntEnum = IntEnum.TWO
var rawValue: Int = enumVar.rawValue
A raw value can be converted to an enum instance by using a dedicated initializer:
var enumVar: IntEnum? = IntEnum(rawValue: 1)
Associated values are used to associate arbitrary data to a specific enum case. Each enum case can have zero or more associated values, declared as a tuple in the case definition:
enum AssociatedEnum {
case EMPTY
case WITH_INT(value: Int)
case WITH_TUPLE(value: Int, text: String, data: [Float])
}
Whereas the type(s) associated to a case are part of the enum declaration, the associated value(s) are instance specific, meaning that an enum case can have different associated values for different enum instances.
Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
What is nil in swift?
Can enum be extended in swift?
What is difference between single and double, in swift?
What are the control transfer statements that are used in ios swift?
Is swift a functional language?
Is equal to string swift?
Why do we use swift? Mention some advantages of swift?
How many types of closures are there in swift?
Does apple use swift internally?
What is dynamic keyword in swift?
What is base class in swift?
What is indexpath in swift?
How to convert nsarray to nsmutablearray in swift?
How to make a method or variable generics in swift?
What is unowned in swift?