`weak` vs `strong` declaration of subview property of a `UIViewController` (http://stackoverflow.com/questions/36495834/is-the-need-to-declare-a-uibutton-property-in-a-uiviewcontroller-as-strong-a-bug)

ViewController.m

//
//  ViewController.m
//  ButtonTest
//
//  Created by Nikolas Burk on 08/04/16.
//  Copyright © 2016 Nikolas Burk. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic, strong) UIButton *someButton;
@property (nonatomic, weak) UITextField *someTextField;

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self.someButton setCenter:self.view.center];
    [self.view addSubview:self.someButton];
    
    [self.someTextField setCenter:CGPointMake(self.view.center.x, self.view.center.y/2.0)];
    [self.view addSubview:self.someTextField];
    
    NSLog(@"subviews: %@", self.view.subviews);
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}


- (UIButton *)someButton
{
    if (!_someButton) {
        UIButton *someButton = [UIButton buttonWithType:UIButtonTypeSystem];
        CGRect someButtonFrame = CGRectMake(0.0, 0.0, 100.0, 44.0);
        someButton.frame = someButtonFrame;
        [someButton setTitle:@"Do something" forState:UIControlStateNormal];
        [someButton addTarget:self action:@selector(someButtonPressed) forControlEvents:UIControlEventTouchUpInside];
        _someButton = someButton;
    }
    return _someButton;
}

- (UITextField *)someTextField
{
    if (!_someTextField) {
        CGRect someTextFieldFrame = CGRectMake(0.0, 0.0, 250.0, 44.0);
        UITextField *someTextField = [[UITextField alloc] initWithFrame:someTextFieldFrame];
        someTextField.layer.borderWidth = 1.0;
        someTextField.layer.borderColor = [UIColor blackColor].CGColor;
        _someTextField = someTextField;
    }
    return _someTextField;
}

- (void)someButtonPressed
{
    NSLog(@"button pressed...");
}


@end