Keep getting error when checking to see if Tip and PriceTxt are empty in Swift

Asked May 19 '20 at 19:45

Active May 19 '20 at 19:54

Viewed 28 times

When entering for the the value for the Tip and the PriceTxt I want to check if it's empty first and return the "Add numbers" if it is but I get the error

Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var PriceTxt: UITextField!
    @IBOutlet weak var Tip: UITextField!
    @IBOutlet weak var totalFinal: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
        totalFinal.text = ""
    }

    @IBAction func Calcualte(_ sender: Any) {
       if  (PriceTxt.text!) == nil || (Tip.text!) == nil
       {
           totalFinal.text = "Add numbers"
       }
       else {
          let price = Double(PriceTxt.text!)!
          let tipPer = Double(Tip.text!)!
          let TipMult =  price * (tipPer/100)
          let TipFinal = Double((round(100*TipMult)/100) + price)
          totalFinal.text = "$\(TipFinal)"
      }   
   }
}

edited May 19 '20 at 19:54

koen

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asked May 19 '20 at 19:45

Jay Ahmed

`UITextField`'s text property will never be nil. Its default value is an empty string. `totalFinal.text = "Add numbers"` will never be executed – Leo Dabus May 19 '20 at 19:47
You should use a custom text field to avoid having to check its value – Leo Dabus May 19 '20 at 19:49
https://stackoverflow.com/a/29783546/2303865 – Leo Dabus May 19 '20 at 19:50
So then how I check if nothing is entered? – Jay Ahmed May 19 '20 at 19:50
Check the link above. There is a sample project there as well – Leo Dabus May 19 '20 at 19:50
The default value will be zero and the user wont be able to add anything else other than numbers to it – Leo Dabus May 19 '20 at 19:51
I still can't seem to figure it out – Jay Ahmed May 19 '20 at 19:54
On what line do you get the error? – koen May 19 '20 at 19:54
@koen he is forcing the text to be converted to Double. If the field is empty or if it has an invalid value it will crash. `let price = Double(PriceTxt.text!)!` `let tipPer = Double(Tip.text!)!` – Leo Dabus May 19 '20 at 19:55
line 29 is the error – Jay Ahmed May 19 '20 at 19:57
1

@JayAhmed You need to use `CurrencyField` instead of a regular `UITextField`. If you need to check its value you can access the field properties `decimal` or `doubleValue` – Leo Dabus May 19 '20 at 19:58
There is no line 29 :) – koen May 19 '20 at 19:58
kkkk OP didn't post the copyright lines – Leo Dabus May 19 '20 at 19:59
Sorry! I was looking at my IDE `let price = Double(PriceTxt.text!)!` – Jay Ahmed May 19 '20 at 20:00
How would I make the conversion? – Jay Ahmed May 19 '20 at 20:06
See the link from @LeoDabus. – koen May 19 '20 at 20:16
I'm new to swift so I'm trying to make the conversation – Jay Ahmed May 19 '20 at 20:27
@JayAhmed sure. The learning curve is steep. But take some time and check the sample project there. All you need is the `CurrencyField.swift` file copied to your project and after adding a textfield to your storyboard use the inspector to change from UITextField to CurrencyField – Leo Dabus May 19 '20 at 20:36
`if (PriceTxt.text!) == "" || (Tip.text!) == ""` This worked O.O – Jay Ahmed May 19 '20 at 20:36
@JayAhmed no need to add parentheses. You can use `UIKeyInput` property `hasText`. Btw it is Swift naming convention to name your objects starting with a lowercase letter – Leo Dabus May 19 '20 at 20:37
`if !priceTxt.hasText || !tip.hasText {` – Leo Dabus May 19 '20 at 20:38
Note that if you use a regular text field the user can still paste regular text on it even if you change the keyboard type. – Leo Dabus May 19 '20 at 20:40
I wasn't looking for optimal solution I just wanted something that worked :D – Jay Ahmed May 19 '20 at 20:43
@JayAhmed glad you solved – Leo Dabus May 19 '20 at 21:17

Keep getting error when checking to see if Tip and PriceTxt are empty in Swift

0 Answers0