Simple label in a viewController's view

gistfile1.txt

- (void)viewDidLoad
{
    [super viewDidLoad];
 
    self.listPriceLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 10, 10)];
    self.listPriceLabel.backgroundColor = [UIColor yellowColor];
    [self.view addSubview:self.listPriceLabel];
    [self.listPriceLabel sizeToFit];

    self.listPriceLabel.text = @"Hello World";
    
    NSDictionary *viewsDictionary = @{@"listPriceLabel": self.listPriceLabel};
    
    NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"|-20-[listPriceLabel]"
                                                                   options:0
                                                                   metrics:nil
                                                                     views:viewsDictionary];
    [self.view addConstraints:constraints];

    [self.view updateConstraintsIfNeeded];
    
    
	// Do any additional setup after loading the view, typically from a nib.
}