I have an Xcode project which has some error. I had only a problem with a variable. I convert the txt string variable to int and this called txtint. When I want to make an calculation I can't because it has null value what is impossible because I give a value in function "pass" and then when I want to subtract I can't because txtint has null value.
//
// ViewController.swift
// Biophere
//
// Created by Coder on 2017. 10. 22..
// Copyright © 2017. Pliz Help. All rights reserved.
//
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var label: UILabel!
#IBOutlet weak var textview: UITextField!
#IBOutlet weak var conv: UILabel!
var text: String? = nil
var txt: String? = nil
var convert: String? = nil
var textint: Int? = nil
var txtint: Int? = nil
#IBAction func pass(_ sender: Any) {
var txt: String {
get {
return textview.text ?? ""
}
set {
textview.text = newValue
}
}
//conv.text = txt
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
label.text = text
txt = textview.text
}
#IBAction func saveButton(_ sender: Any) {
let textint = Int(text!)
let txtint = Int(txt!)
convert = String(textint! - txtint!)
conv.text = txt
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
ERROR: Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)
var text: String = ""
var txt: String = ""
var convert: String = ""
var textint: Int = 0
var txtint: Int = 0
#IBAction func saveButton(_ sender: Any) {
if let textint = Int(text), let txtint = Int(txt) {
convert = String(textint - txtint)
conv.text = txt
}else{
print("handle it")
}
}
Suggestion: Try to give variable name descriptive it is a basic thing for development.
Related
What am I doing wrong?
I get this error:
let letterString = sender.title(for: .normal)! // Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value
when I tried to get the title of a button in swift like below:
import UIKit
class ViewController: UIViewController {
// My IBOutlets
#IBOutlet var treeImageView: UIImageView!
#IBOutlet var correctWordLabel: UILabel!
#IBOutlet var scoreLabel: UILabel!
// My Outlet Collection
#IBOutlet var letterButtons: [UIButton]!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
// Begin the round.
newRound()
}
var listOfWords = ["estufa", "nevera", "computadora", "empanada", "chuleta", "camarones", "brincar", "correr", "caminar", "tigre", "jirafa", "mono", "kisseemmee", "Tampa", "Orlando"]
let incorrectMovesAllowed = 7
let totalWins = 0
let totalLosses = 0
// My IBActions
#IBAction func letterButtonPressed(_ sender: UIButton) {
sender.isEnabled = false
let letterString = sender.title(for: .normal)! // Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value
let letter = Character(letterString.lowercased())
currentGame.playerGuessed(letter: letter)
updateUI()
}
var currentGame: Game!
func newRound() {
let newWord = listOfWords.removeFirst()
currentGame = Game(word: newWord, incorrectMovesRemaining: incorrectMovesAllowed, guessedLetters: [])
updateUI()
}
func updateUI() {
scoreLabel.text = "Wins: \(totalWins), Losses: \(totalLosses)"
treeImageView.image = UIImage(named: "Tree \(currentGame.incorrectMovesRemaining)")
}
}
// Game.swift file code:
import Foundation
struct Game {
var word: String
var incorrectMovesRemaining: Int
var guessedLetters: [Character]
mutating func playerGuessed(letter: Character) {
guessedLetters.append(letter)
if !word.contains(letter) {
incorrectMovesRemaining -= 1
}
}
}
I'm a newbie. This is my first program. I appreciate if you code the solution.
You can get the title of the UIButton using titleLabel property. Check the below code.
sender.titleLabel?.text
As the above code returns optional, you can use optional chain to safely get the string
if let titleLabel = sender.titleLabel {
let title = titleLabel.text
}
OR
You can also use the currentTitle property as below.
sender.currentTitle
You can use:
sender.titleLabel.text
I have searched for similar questions, but they could not resolve my issue, so I hope it's ok, that I am asking it again. Here is my code:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBOutlet weak var revealLabel: UILabel!
#IBOutlet weak var scoreLabel: UILabel!
#IBOutlet weak var textField: UITextField!
var userGuess: Int
var heldUpFingers: Int
var score: Int = 0
#IBAction func startGame(sender: UIButton) {
userGuess = Int(textField.text!)!
if textField.text == nil {
revealLabel.text = "Please enter a number from 1 to 5"
} else if userGuess > 5 {
revealLabel.text = "Please enter a number from 1 to 5"
} else {
heldUpFingers = Int(arc4random_uniform(5) + 1)
if heldUpFingers == userGuess {
revealLabel.text = "You guessed right!"
score += 1
scoreLabel.text = String(score)
} else {
revealLabel.text = "Wrong, it was \(heldUpFingers)"
}
}
}
}
It gives me the error "Class 'ViewController' has no initializers" in the 3rd line. Thanks in advance!
It is because userGuess and heldUpFingers aren't assigned yet. You can either make these optional by adding a ? after the Int or by setting a default value to them. So either:
var userGuess: Int?
var heldUpFingers: Int?
You will then need to unwrap them/check there not nil later in your code like this:
if userGuess != nil {
//now safely use userGuess!
}
Or
var userGuess: Int = 0
var heldUpFingers: Int = 0
I created a view to use as background and I would like to change its color when label text is greater or less than variable number. The script is okay but the color is not changing.
Thanks in advance.
import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
#IBOutlet weak var localName: UITextField!
#IBOutlet weak var localNameLabel: UILabel!
#IBOutlet weak var localTemp: UILabel!
#IBAction func getData(sender: AnyObject) {
getWeatherData("http://api.openweathermap.org/data/2.5/weather?q=" + localName.text! + "")
}
#IBOutlet weak var fundo: UIView!
override func viewDidLoad() {
super.viewDidLoad()
getWeatherData("http://api.openweathermap.org/data/2.5/weather?q=London")
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func getWeatherData(urlString: String){
let url = NSURL (string: urlString)
let task = NSURLSession.sharedSession().dataTaskWithURL(url!) { (data, response, error) in
dispatch_async(dispatch_get_main_queue(), {
self.setLabels(data!)
})
}
task.resume()
}
func setLabels(weatherData: NSData) {
do {
let json = try NSJSONSerialization.JSONObjectWithData(weatherData, options:NSJSONReadingOptions.MutableContainers) as! NSDictionary
print(json)
//localNameLabel.text = json[("name")] as? String
if let name = json[("name")] as? String {
localNameLabel.text = name
}
if let main = json[("main")] as? NSDictionary {
if let temp = main[("temp")] as? Double {
//convert kelvin to celsius
let ft = (temp - 273.15)
let myString = ft.description
localTemp.text = myString
self.changeColor()
}
}
} catch let error as NSError {
print(error)
}
var number : Float
func changeColor(){
number = 19.0
if(Float(localTemp.text!) < number){
fundo.backgroundColor = .blueColor()
}else{
fundo.backgroundColor = .orangeColor()
}
}
}
}
Edited to post the entire script
In your view controller you need to add UITextFieldDelegate which will allow you to access methods related to your text field. The top of your view controller should look like this:
class ViewController: UIViewController,UITextFieldDelegate //set delegate to class
You then need to set the delegate of your text field to self in viewDidLoad and add a target for when the text field changes:
override func viewDidLoad() {
super.viewDidLoad()
localTemp.delegate = self //set delegate to this vc
localTemp.addTarget(self, action: "textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
}
You can then implement this method which will run on every key press and you need to call your changeColor() method as above:
func textFieldDidChange(textField: UITextField) {
self.changeColor()
}
import UIKit
import Alamofire
class ViewController: UIViewController {
#IBOutlet weak var uiNameSearch: UITextField!
#IBOutlet weak var uiGivenName: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func searchForName(sender: UIButton) {
let header = ["Accept" : "application/json"]
let name = uiNameSearch.text!
let given = uiGivenName.text!
Alamofire.request(.GET, "https://open-ic.epic.com/FHIR/api/FHIR/DSTU2/Patient?family=\(name)&given=\(given)", headers: header).responseJSON { response in
let patient = response.result.value!
if let entry = patient.objectForKey("entry") {
if let link = entry[0].objectForKey("link") {
if let url = link[0].objectForKey("url") {
let fullNameArr = url.componentsSeparatedByString("/")
print(fullNameArr[fullNameArr.count-1])
}
//print(link)
}
}
}
}
}
My Patient class is:
class Patient {
var name: String
var given: String
var id: String
init(name: String, given: String, id: String) {
}
}
I want to use the response in init to create objects, how can I do this?
The program is suppose to change F TO C and reverse. With the Switch it changes from on to off and on is suppose to be C to f and off is F to c and entering the # underneath in the text field.
When clicking the submit button it takes whats in the text field transfers it to an in preforms the algorithm and then displays it in the textfield.
I believe the conversion is going correctly but will not display the actual result. Or the way its being converted is wrong.
#IBOutlet weak var buttonClicked: UIButton!
#IBOutlet weak var mySwitch: UISwitch!
#IBOutlet weak var myTextField: UITextField!
#IBOutlet weak var User: UITextField!
func stateChanged(switchState: UISwitch) {
if switchState.on {
myTextField.text = "Convert to Celius"
} else {
myTextField.text = "Convert to Farheniet"
}
}
#IBAction func buttonClicked(sender: UIButton) {
if mySwitch.on {
var a:Double? = Double(User.text!)
a = a! * 9.5 + 32
User.text=String(a)
mySwitch.setOn(false, animated:true)
} else {
var a:Double? = Double(User.text!)
a = a! * 9.5 + 32
User.text=String(a)
mySwitch.setOn(true, animated:true)
}
}
I am using an older version of XCode(6.4) so my code will be a little bit different from yours. From what I understand your function buttonClicked should take the argument of AnyObject instend of UIButton. Also you do not call the function stateChanged in your code at all. The following code should help achieve what you trying to do.
#IBOutlet weak var mySwitch: UISwitch!
#IBOutlet weak var myTextField: UITextField!
#IBOutlet weak var User: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
// sets the textfield to the intended conversion on load.
if mySwitch.on {
myTextField.text = "Convert to Celius"
}
else {
myTextField.text = "Convert to Farheniet"
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// changes the myTextFiled text to the intended conversion when the switch is manually switched on or off
#IBAction func switched(sender: AnyObject) {
if mySwitch.on {
myTextField.text = "Convert to Celsius"
}
else {
myTextField.text = "Convert to Fahrenheit"
}
}
// changes the myTextField text to intended reverse conversion after the buttonClicked func is completed.
func stateChanged(switchState: UISwitch) {
if switchState.on {
myTextField.text = "Convert to Celsius"
}
else {
myTextField.text = "Convert to Fahrenheit"
}
}
// do the intended conversion(old version of XCode 6.4)
#IBAction func buttonClicked(sender: AnyObject) {
if mySwitch.on {
var a = (User.text! as NSString).doubleValue
a = (a-32)*(5/9)
User.text="\(a)"
mySwitch.setOn(false, animated:true)
stateChanged(mySwitch)
}
else {
var a = (User.text! as NSString).doubleValue
a = a * (9/5) + 32
User.text="\(a)"
mySwitch.setOn(true, animated:true)
stateChanged(mySwitch)
}
}