swift - Why Are My Default Property Values Still Showing as Parameters in Init()? -

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i have protocol describes marine water parameter needs tested:

protocol parameter {      var name: string { }     var unit: unit { }     var value: double { }  }

i have struct, calcium, conforms parameter:

struct calcium: parameter {      var name: string = "calcium"     var unit: unit = unitdispersion.partspermillion     var value: double  }

since name , unit parameters of calcium have default values, why need provide them in init method? shouldn't need provide value value?

i trying understand protocol-oriented-programming , appreciate little guidance here.

enter image description here

  1. this has nothing whatever protocols.

  2. you not have provide initializer value. have not provided any initializer. therefore initializer have 1 provided automatically, , initializer memberwise initializer wants parameters properties.

if don't that, write initializer yourself:

struct calcium: parameter {     var name: string = "calcium"     var unit: unit = unitdispersion.partspermillion     var value: double     init(value:double) {self.value = value} }

now legal say:

let c = calcium(value:2)

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