Check If UITextField Contains Value

In this tutorial, you will learn how to check if a UITextField contains a value in Swift. I will cover the following topics:

1. Understanding the isEmpty property.
2. Using the isEmpty property to check if a UITextField is empty.
3. Handling the case when the UITextField is empty.

Step 1: Understanding the isEmpty Property

In Swift, strings have a built-in property called isEmpty. This property returns true if the string has zero characters and false otherwise. Similarly, UITextField has a text property that holds the current text displayed in the text field. To check if this text is empty,  you can use the isEmpty property.

Step 2: Using the isEmpty Property to Check if a UITextField is Empty

To check if a UITextField is empty, you can use the isEmpty property in combination with optional chaining (?) and force unwrapping (!). Here’s how you can do it:

if (firstNameTextField.text?.isEmpty)! {
 // The UITextField is empty
}

if (firstNameTextField.text?.isEmpty)! {
 // The UITextField is empty
 let alert = UIAlertController(title: "Error", message: "Please enter a value.", preferredStyle: .alert)
 alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
 present(alert, animated: true, completion: nil)
}

import UIKit

class ViewController: UIViewController {
    // Create UITextField
    let myTextField: UITextField = UITextField(frame: CGRect(x: 0, y: 0, width: 300.00, height: 30.00))

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Position UITextField in the center of the view
        myTextField.center = self.view.center

        // Set UITextField placeholder text
        myTextField.placeholder = "Enter something..."
        myTextField.frame = CGRect(x: 0, y: self.view.bounds.height - 250, width: 200, height: 50)

        // Add UITextField as a subview
        self.view.addSubview(myTextField)

        // Create a Button
        let checkButton = UIButton(type: .system)
        checkButton.setTitle("Check", for: .normal)
        checkButton.frame = CGRect(x: 0, y: self.view.bounds.height - 100, width: 100, height: 50)
        checkButton.center.x = self.view.center.x
        checkButton.addTarget(self, action: #selector(buttonClicked), for: .touchUpInside)

        // Add Button as a subview
        self.view.addSubview(checkButton)
    }

    @objc func buttonClicked() {
        if (myTextField.text?.isEmpty)! {
            let alert = UIAlertController(title: "Error", message: "Please enter a value.", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
            present(alert, animated: true, completion: nil)
        } else {
            let alert = UIAlertController(title: "Success", message: "The UITextField contains a value.", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
            present(alert, animated: true, completion: nil)
        }
    }
}

In this code, I override the viewDidLoad() method, which is called after the controller’s view is loaded into memory. Inside this method, I create a UITextField, configure its properties, and add it as a subview to the view controller’s view. I also create a button and add it as a subview to the view controller’s view.

The buttonClicked() method is connected to the button’s touchUpInside event. When the button is clicked, this method is called. Inside this method, I check if the UITextField is empty and display an alert accordingly.

Conclusion