Convert String to Double with Currency - ios

Question

NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle: NSNumberFormatterCurrencyStyle];
double value = [[numberFormatter numberFromString: ProviderTripRate.text] doubleValue];
[User setDouble:value forKey:#"Trip_Rate"];
NSLog(#" %# %f " , ProviderTripRate.text , value );
If the data inside ProviderTripRate.text is 2.75 then value is 0 wrong
If the data inside ProviderTripRate.text is $2.75 then value is 2.75 correct
How do you reliably convert from the string to a double value
NOTE that the text string may or may NOT have the local currency symbol ($ as shown above)
but it should always convert
Thanks in advance

Answer 1

Try this:
NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];
[numberFormatter setNumberStyle: NSNumberFormatterCurrencyStyle];
NSNumber* number = [numberFormatter numberFromString:ProviderTripRate.text]
if (!number) {
[numberFormatter setNumberStyle: NSNumberFormatterDecimalStyle];
number = [numberFormatter numberFromString:ProviderTripRate.text];
}
double value = [number doubleValue];

Answer 2

Try this:
if ([providerTripRate.text hasPrefix:#"$"]) {
// use NSNumberFormatter to obtain the value
} else {
float theValue = [providerTripRate.text doubleValue];
}
etc.

Answer 3

extension String {
/// Creates a Double from the string
///
/// Tries various ways of extracting a number, currently handling the following formats
/// - 1000
/// - 1000.00
/// - 1,000.00
/// - $1,000.00
///
/// - Returns: Double value, or 0.0 if a non numerical String is passed
func asDouble() -> Double {
if let double = Double(self) {
return double
}
let formatter = NumberFormatter()
if let number = formatter.number(from: self) {
return number.doubleValue
}
formatter.numberStyle = .currency
if let number = formatter.number(from: self) {
return number.doubleValue
}
formatter.currencySymbol = ""
formatter.internationalCurrencySymbol = ""
if let number = formatter.number(from: self) {
return number.doubleValue
}
return 0
}
}