CODEWITHSUNDEEP
iosswiftintswift2
Shawn Patel
Shawn Patel

Reputation: 99

Converting String to Integer iOS + Swift 2.0

I am accessing an API for weather and when I parse the JSON the result is a string. Since, the value I am accessing is a number, I want to convert it to an integer, but when the string has a decimal value, the string does not convert to an int. My code:

let UVIndex = swiftyJSON["current_observation"]["UV"].stringValue
let cityName = swiftyJSON["current_observation"]["display_location"]["full"].stringValue
if let UVIndexInt = Int(UVIndex) {
    print("Successfully converted! \(UVIndexInt)")
    self.UVIndexString = String(stringInterpolationSegment: UVIndex)
}
dispatch_async(dispatch_get_main_queue()) {
    self.UVIndexButton.setTitle(self.UVIndexString, forState: UIControlState.Normal)
    self.cityName.text = cityName
}

Upvotes: 1

Views: 330

Answers (3)

dfrib
dfrib

Reputation: 73206

Another alternative; in essence same technique as in appzYourLife answer, but using a closure:

let toInt : (String) -> (Int?) = { Double($0) == nil ? nil : Int(Double($0)!) }

var text = "1.1"
toInt(text)           // 1
text = "notANumber"
toInt(text)           // nil

Note that both this and the accepted solution will yield a runtime exception if, for some reason, text contains a number literal (in a string, naturally) which is larger than Int.max (on my 64 bit system: 9223372036854775807). Possibly not likely, but if you want to take extra care (some crazy UV index?) you should take measures against this (e.g. truncating).

Upvotes: 1

Luca Angeletti
Luca Angeletti

Reputation: 59536

You can try to convert the String to Double and then to Int.

let text = "1.1"

if let textAsDouble = Double(text) {
    let textAsInt = Int(textAsDouble)
    print(textAsInt)
}

Upvotes: 5

JAL
JAL

Reputation: 42479

An alternate solution without converting the the input string to a Double and then an Int would be to use an NSNumberFormatter to create an NSNumber from your string. This way, you can get an Int or the fixed-width Int32 type from your string:

let val = "1.1"

let formatter = NSNumberFormatter()
formatter.numberStyle = .DecimalStyle

formatter.numberFromString(val)?.intValue // Int32
formatter.numberFromString(val)?.integerValue // Int

Upvotes: 4

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