An enumeration is a user-defined data type that consists of a set of related values. We use enumerations to define your own kind of value in Swift. An enum is a data type that consists a set of named values, called members. We use keyword enum to define the enumerated data types.
Enums are much more flexible and do not have to provide a value for each case of the enumeration. If a value is provided for each enumeration case, the value can be a string, a character, or a value of any integer or floating-point type.
Syntax:
We introduce enumerations with the “enum” keyword and place their definition within a pair of braces.
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enum Name { // enumeration definition } |
For Example:
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enum Gender{ case male case female } |
The defined values in an enumeration are its enumeration cases. We always use the case keyword to introduce new enum cases.
We can now define a variable as an enumeration case like:
var gender: Gender = Gender.male or
var gender = Gender.male
Switch Statement using enums :
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switch gender{ case .male: print("Gender is male") case .female: print("Gender is female") } |
We do not need to define a default case for enum switch statement as we have used all the possible enum members. If we do not check all the enum members, then we need a default case.
Enums with User Defined Values:
Enums can not have a user-defined value until and unless it has a raw type.
Example:
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enum Gender{ case male = 1 case female } |
This code in the example will throw an error since we haven’t defined a raw type to enum. To define a value to enum, it must have a raw type, for example:-
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enum Number: Int{ case one = 1 case two = 2 case three } |
This now enumerates the values and assigns numbers. One with 1 and genres, Two with 2 and so on. If we use integers for raw values, they auto-increment from the previous value if no value is specified.
Enums with methods:
Enums can have methods that can be used on enum cases. For example:
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enum Days: String{ case Monday case Tuesday func getDay() -> String{ return self.rawValue } } |
We can call this function like Days.Monday.getDay, which will return rawValue of case Monday, means output: Monday.
Conclusion:
In this blog, we learned about enums. Enums can have methods, subscripts, and computed properties, but enums cannot have stored properties. To know more about enums, you can look here.
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