Pass parameter's datatype not consistent with it's declared

Question

I followed the treehouse lesson,

let currentWeather = Current(weatherDictionary: weatherDictionary)

And don't know why I should use Current(weatherDictionary: weatherDictionary) to pass compile

But not Current(weatherDictionary: NSDictionary)

Because I think I declared the weatherDictionary as NSDictionary type

Answer 1 · 2014-10-15T11:12:54Z

October 15, 2014 11:12am

Hi Poc,

Structs can be slightly confusing as the constructor always uses named parameters which means even though we haven't declared something like #weatherDictionary we still need to called the parameter name when creating a new Current struct, so this is how it works visually.

Current(
  weatherDictionary: // This is the named parameter in the `init` constructor function
  weatherDictionary  // This is the `NSDictionary` we're passing to the `Struct`
)

The only time you need to declare a type is when you're creating a new variable for example.

var myVar: String = "Treehouse is awesome!"

// This is the same as
var myVar = "Treehouse is awesome!"

// And because it's already assigned an explicit type we can assign a new value to the variable without re-declaring the type
myVar = "Now it's even more awesome"

Hope that helps.

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Poc Hsu

Poc Hsu

Pass parameter's datatype not consistent with it's declared

1 Answer

Chris Shaw

Chris Shaw