不同区域 Swift 中的字符串到双精度转换 nil

Question

There is a text field

@IBOutlet weak var txt: UITextField!

When I tried to convert the value of txt into Double its worked fine in US region.

For example

let magicNumber = Double(txt.text ?? "0.0")

If I type 12 UITextField then 12 assigned on magicNumber

Then I changed the region to Germany.

let magicNumber = Double(txt.text ?? "0.0")

If I type 12,8 UITextField then the magicNumber is nil.

I need a correct double value like: 12.8

How could I achieve this? Please suggest to me the correct way.

Answer 1

Careful handling of localized numeric strings

let inputString = "12,8" 
let formatter = NumberFormatter()
formatter.locale = Locale.current // Locale(identifier: "de")
let number = formatter.number(from: inputString) 
print(number) // 12.8