demonstration that removing object from superview requires re-alloc of that object

gistfile1.m

//
//  ViewController.m
//  remove from superview demo
//
//  Created by Rex Fatahi on 5/17/14.
//  Copyright (c) 2014 aug2uag. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()
{
    UIView* aView;
}

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.
    
    aView = [[UIView alloc] initWithFrame:CGRectMake(40, 40, 240, 240)];
    aView.backgroundColor = [UIColor redColor];
    [self.view addSubview:aView];
    
    UIButton* aButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [aButton setTitle:@"do it" forState:UIControlStateNormal];
    [aButton addTarget:self action:@selector(doIT:) forControlEvents:UIControlEventTouchUpInside];
    aButton.frame = CGRectMake(20, self.view.bounds.size.height - 64, 280, 44);
    [self.view addSubview:aButton];
    
}

- (void)doIT:(UIButton *)sender
{
    if (!sender.selected) {
        [aView removeFromSuperview];
    } else {
        [self.view addSubview:aView];
    }
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end