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iOS

Blair Rorani
Blair Rorani
6,658 Points
Posted by Blair Rorani
Blair Rorani
6,658 Points

Why do I need to add "" to string parameters manually?

If I'm using the function

carpetCostHaving(length: 10, width: 20, carpetColor: String)

carpetColor: String needs the value for the string to have "" added manually (e.g carpetColor: "red". Why is this if Swift already knows it should expect a string?

1 Answer

Jon Brantingham
Jon Brantingham
7,860 Points

I guess a better way to put it is that the compiler requires a string to be the ultimate value there. Swift doesn't necessarily know what you are going to give it. Below is an example where I give it different values.

First a string "Tan". Second is a constant firstColor with the value of "Tan". Third is a constant notAColor with an Int value.

The parameter accepts all three as an argument, but "notAColor" gives an error.

let firstColor = "Tan"
let notAColor = 3

func carpetColorFunc(carpetColor: String) -> String {
    return "My carpet color is \(carpetColor)"
}

print(carpetColorFunc(carpetColor: "Tan"))
//Prints "My carpet color is Tan"

print(carpetColorFunc(carpetColor: firstColor))
//Prints "My carpet color is Tan"

carpetColorFunc(carpetColor: notAColor)
//Does not print, but gives error message "Cannot convert value of type 'Int' to expected argument type 'String'"