swift - Can I change the Associated values of a enum? -

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i reading swift tour document, , facing problem. here code:

enum simpleenum {     case big(string)     case small(string)     case same(string)      func adjust() {         switch self {         case let .big(name):             name +=  "not"         case let .small(name):             name +=  "not"         case let .same(name):             name +=  "not"         }     } }

the function adjust() won't work, wonder if there way change associated value of enum, , how?

your immediate problem you're attempting change value of immutable variable (declared let) when should declaring var. won't solve particular problem though since name variable contains copy of associated value, in general need aware of.

if want solve this, need declare adjust() function mutating function , reassign self on case case basis new enum value associated value composed old 1 , new one. example:

enum simpleenum{     case big(string)     case small(string)     case same(string)      mutating func adjust() {         switch self{         case let .big(name):             self = .big(name + "not")         case let .small(name):             self = .small(name + "not")         case let .same(name):             self = .same(name + "not")         }     } }  var test = simpleenum.big("initial") test.adjust()  switch test { case let .big(name):     print(name) // prints "initialnot" case let .small(name):     print(name) case let .same(name):     print(name) }

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