Firstname validation in iOS swift4? - Stack Overflow

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>IDECodeSnippetCompletionPrefix</key>
	<string>snippetAlert</string>
	<key>IDECodeSnippetCompletionScopes</key>
	<array>
		<string>All</string>
	</array>
	<key>IDECodeSnippetContents</key>
	<string>let alertController = UIAlertController(title: &lt;#T##String?#&gt;, message: &lt;#T##String?#&gt;, preferredStyle: &lt;#T##UIAlertController.Style#&gt;)
let firstAction = UIAlertAction(title: &lt;#T##String?#&gt;, style: .default, handler: &lt;#T##((UIAlertAction) -&gt; Void)?##((UIAlertAction) -&gt; Void)?##(UIAlertAction) -&gt; Void#&gt;)
let cancelAction = UIAlertAction(title: &lt;#T##String?#&gt;, style: .cancel, handler: nil)

alertController.addAction(firstAction)
alertController.addAction(cancelAction)
present(alertController, animated: true)</string>
	<key>IDECodeSnippetIdentifier</key>
	<string>8C458AD7-C631-457B-85CC-D2501E425D59</string>
	<key>IDECodeSnippetLanguage</key>
	<string>Xcode.SourceCodeLanguage.Swift</string>
	<key>IDECodeSnippetSummary</key>
	<string></string>
	<key>IDECodeSnippetTitle</key>
	<string>UIAlertController</string>
	<key>IDECodeSnippetUserSnippet</key>
	<true/>
	<key>IDECodeSnippetVersion</key>
	<integer>2</integer>
</dict>
</plist>

@IBAction func doSomething()
@IBAction func doSomething(sender: UIButton)
@IBAction func doSomething(sender: UIButton, forEvent event: UIEvent)

[[NSProcessInfo processInfo] operatingSystemVersion]

import 'package:flutter/material.dart';

void main() {
  runApp(
    new MaterialApp(
      title: 'Hello World App',
      home: new myApp(),
    )
  );
}

class myApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Hello World App'),
      ),
      body: new Center(
        child: new Text(
          'Hello, world!'
        ),
      ),
    );
  }
}

override func viewDidLoad() {
    super.viewDidLoad()
    // Swift block syntax (iOS 10+)
    let timer = Timer(timeInterval: 0.4, repeats: true) { _ in print("Done!") }
    // Swift >=3 selector syntax
    let timer = Timer.scheduledTimer(timeInterval: 0.4, target: self, selector: #selector(self.update), userInfo: nil, repeats: true)
    // Swift 2.2 selector syntax
    let timer = NSTimer.scheduledTimerWithTimeInterval(0.4, target: self, selector: #selector(MyClass.update), userInfo: nil, repeats: true)
    // Swift <2.2 selector syntax
    let timer = NSTimer.scheduledTimerWithTimeInterval(0.4, target: self, selector: "update", userInfo: nil, repeats: true)
}

// must be internal or public. 
@objc func update() {
    // Something cool
}

// Preferred status bar style lightContent to use on dark background.
// Swift 3
override var preferredStatusBarStyle: UIStatusBarStyle {
    return .lightContent
}

// MARK: - Properties

// MARK: - IBOutlets

// MARK: - Life cycle

// MARK: - Set up

// MARK: - IBActions

// MARK: - Navigation

// MARK: - Network Manager calls

// MARK: - Extensions

import UIKit

extension UITableView {
    
    func dequeueReusableCell<T: UITableViewCell>() -> T {
        return dequeueReusableCell(withIdentifier: NSStringFromClass(T.self)) as! T
    }
}

//using: let cell: ExampleTableViewCell = tableView.dequeueReusableCell()

#include <iostream>
#include "unordered_set"
#include "basicActions.h"
using namespace std;

void createLoop(Node *head)
{
    Node *p = head;

    while (p->next != nullptr)
    {
        p = p->next;
    }
    p->next = head;
    return;
}

bool detectLoop(Node *head)
{
    unordered_set<Node *> s;
    Node *p = head;

    while (p != nullptr)
    {
        if (s.find(p) != s.end())
            return true;

        s.insert(p);
        p = p->next;
    }
    return false;
}

int main()
{
    Node *head = nullptr;
    insertAtEnd(head, 1);
    insertAtEnd(head, 2);
    insertAtEnd(head, 3);
    insertAtEnd(head, 4);
    insertAtEnd(head, 5);

    createLoop(head);

    detectLoop(head) ? cout << "Loop Detected.." << '\n' : cout << "No Loop Detected.." << '\n';
}

#include <iostream>
using namespace std;

struct hashing
{
    int value;
    int key;
};


void put(int value, hashing hash[],int n) {
    hash[value % n].value = value;
    hash[value % n].key = (value % n);
}

int get(int key, hashing hash[]) {
    return hash[key].value;
}

int main()
{
    int n;
    
    struct hashing hash[n];
    cin >> n;
    for (int t=0;t<n;t++) {
        put(t+1,hash,n);
        cout << "Inserted : " << (t+1) << endl;
    }
    int temp;
    cin >> temp;
    cout << get(temp,hash) << endl;
}

let url = URL(string: image.url)
let data = try? Data(contentsOf: url!) //make sure your image in this url does exist, otherwise unwrap in a if let check / try-catch
imageView.image = UIImage(data: data!)

function aaa(a, b){
return a+b;
}

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    func getDateTime(_ timeStamp : String,_ format: String) -> String {
        var t1 = Int(timeStamp) ?? 1
         t1 = t1/1000
        let date = NSDate(timeIntervalSince1970: TimeInterval(t1))
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = format
        let dateString = dateFormatter.string(from: date as Date)
        print("Date = \(dateString)")
        return dateString
    }

var imagePicker = UIImagePickerController()

func enableImageViewTapGesture()
    {
        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(profileImageTapped(tapGesturerecognizer:)))
        profileImageView.isUserInteractionEnabled = true
        profileImageView.addGestureRecognizer(tapGestureRecognizer)
    }
    
    @objc func profileImageTapped(tapGesturerecognizer: UITapGestureRecognizer){

        if UIImagePickerController.isSourceTypeAvailable(.savedPhotosAlbum){
            print("Button capture")
            imagePicker.delegate = self
            imagePicker.sourceType = .savedPhotosAlbum
            imagePicker.allowsEditing = true
            present(imagePicker, animated: true, completion: nil)
        }
        else {
            print("No NO")
        }
    }

extension SignupViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        
        if let pickedImage = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
            
            profileImageView.layer.cornerRadius = profileImageView.bounds.width/2
            profileImageView.image = pickedImage
        }
        self.dismiss(animated: true, completion: nil)
    }
    
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        dismiss(animated: true, completion:nil)
    }
}