string to double swift
let lessPrecisePI = Float("3.14") let morePrecisePI = Double("3.1415926536") let invalidNumber = Float("alphabet") // nil, not a valid number //Unwrap the values to use them using if/let if let cost = Double(textField.text!) { print("The user entered a value price of \(cost)") } else { print("Not a valid number: \(textField.text!)") } //You can convert formatted numbers and currency using the NumberFormatter class. let formatter = NumberFormatter() formatter.locale = Locale.current // USA: Locale(identifier: "en_US") formatter.numberStyle = .decimal let number = formatter.number(from: "9,999.99")
