How do I convert a textField`s String to a Double in xCode with Swift

Question

I am making a very simple beginner project where I receive the data from a textField and store it in a Double var. I have tried the .toDouble() but it doesn´t seem to exist. Any help please?

Answer 1

You can simply put the string in as a parameter when creating a double!

let double = Double(textView.text!)

Answer 2

Add the following extension and use .toDouble()

extension String {
func toDouble() -> Double? {
    return NSNumberFormatter().numberFromString(self)?.doubleValue
 }
}

Like

var someString = “30.23"
var someDouble = someString.toDouble()

Answer 3

extension String {
    var doubleValue: Double {
        return Double(self) ?? 0
    }
}

Usage:

let inputString = "32.1"
let myDouble = inputString.doubleValue   // 32.1

Answer 4

if let doubleValue = Double(textView.text!) {

} else {
    print("Not a valid number: \(textView.text!)")
}