IOS SWIFT: the declaration is only valid in the file area
Usually in C # I used to implement extension methods in a separate class (named "ExtensionMethods") and used in the project.
Here in my first quick iphone app I need to implement some extension methods of the String class but giving me this error
This works great with a fast playground, but not sure how to use in a real project. really appreciate if someone can guide me with this. Thank you.
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1 answer
The extension must be at the root level - not inject them into a class or whatever. So just write:
import UIKit
extension String {
var doubleValue: Double {
...
}
}
extension String {
func doubleValueT() -> Double {
...
}
}
Note that you can also combine them into one extension:
import UIKit
extension String {
var doubleValue: Double {
...
}
func doubleValueT() -> Double {
...
}
}
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