CODEWITHSUNDEEP
iosswift
JAY LEWIS
JAY LEWIS

Reputation: 1

How do I store data (user input from a textfield)

I am using Swift and I want to know how I can store user input as a variable (it’s a double).

I'm still in the learning states so I have been watching youtube tutorials on the situation but nothing helped.

My code:

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var userInput: UITextField!
    override func viewDidLoad() {
        userInput.delegate = self
    }

    @IBAction func Increment(_ sender: UIButton) {
        var inc = 0
        userInput = userInput + inc
    }

    @IBAction func Decrement(_ sender: UIButton) {

    }
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        userInput.resignFirstResponder()

    }

}

extension ViewController: UITextFieldDelegate{
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()

        return true
    }

}

The user will be able to enter a number and increment or decrement the number by a certain input value.

Upvotes: 0

Views: 1334

Answers (4)

Abhi Yaduwanshi
Abhi Yaduwanshi

Reputation: 410

//fetch any number from textfield 

func getValueFromTextfield() -> Double?{

  guard let text = userInput.text else {
      print("Missing user input")
      return nil 
  }

  guard let doubleValue = Double(text) else {
      print("parse failure")
      return nil 
  }
return doubleValue
}

// Now for increment and decrement we have methods be like, Am assuming certain input value as 1 to be used for increment and decrement replace this if needed 

func increment(){

// get value
   if let value = getValueFromTextfield(){
    userInput.text = “\(value + 1)” // increment by 1 
   }
}

func decrement(){

 // get value and check if it’s greater than zero
  if let value = getValueFromTextfield(), value > 0{
    userInput.text = “\(value - 1)” // decrement by 1
  }
}

@IBAction func Increment(_ sender: UIButton) {
    increment()
}

@IBAction func Decrement(_ sender: UIButton) {
    decrement()
}

These method will help you achieve increment or decrement operation without need to store value in any variable.

If you still want to save value in variable just simply store value returned from method let valueToStore = getValueFromTextfield()

Upvotes: 2

Mudasir Syed
Mudasir Syed

Reputation: 131

@IBAction func Increment(_ sender: UIButton) {
    var inc = 0
    userInput.text = ( Double(userInput.text) + Double(inc) ).rounded(toPlaces: 1)
}

Upvotes: 0

atul
atul

Reputation: 166

@IBAction func Increment(_ sender: UIButton) {
    if let text = userInput.text, var doubleText = Double(text) {
        doubleText = doubleText + 1
        userInput.text = "\(doubleText)"
    }
}

Similarly you can write for Decrement.

Upvotes: 0

Vyacheslav
Vyacheslav

Reputation: 27211

Your code won't compile correctly but the answer to your question is:

let doubleValue = Double(userInput.text!)! converts your code to double

or better using optional unwrapping:

guard let text = userInput.text else {
    print("text of userInput is nil")
    return
}
guard let doubleValue = Double(text) else {
    print("Impossible to parse \(text) into Double")
    return
}
print(doubleValue)

Upvotes: 1

Related Questions