create and hide UILabel - objective-c

Question

I created a UILabel programatically and triggering a button I would like to hide the same label. This is my code:
UILabel *nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 100, 320, 100)];
nameLabel.text = #"TEXT";
nameLabel.backgroundColor = [UIColor greenColor];
nameLabel.numberOfLines = 5;
nameLabel.font = [UIFont boldSystemFontOfSize:12];
[self.view addSubview:nameLabel];
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:#"Hide" style:UIBarButtonItemStyleBordered target:self action:#selector(back)];
- (IBAction)back{
self.navigationItem.rightBarButtonItem=nil;
[nameLabel setHidden: YES]; not working
nameLabel.hidden = YES; not working
}
Am I missing something?

Answer 1

This is also another way to do same
UILabel *nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 100, 320, 100)];
nameLabel.text = #"TEXT";
nameLabel.tag = 1001;
nameLabel.backgroundColor = [UIColor greenColor];
nameLabel.numberOfLines = 5;
nameLabel.font = [UIFont boldSystemFontOfSize:12];
[self.view addSubview:nameLabel];
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:#"Hide" style:UIBarButtonItemStyleBordered target:self action:#selector(back)];
- (IBAction)back{
self.navigationItem.rightBarButtonItem=nil;
UILabel *tempLabel = (UILabel *)[self.view viewWithTag:1001];
[tempLabel setHidden: YES];
tempLabel.hidden = YES;
}

Answer 2

In order for the button to be accessible from other methods, you need to assign it to an instance variable (whether directly or via a property) rather than assigning it to a local variable. The proper way to declare the property is
#property(nonatomic, strong) UILabel *nameLabel;
which you can then assign to using
self.nameLabel = [[UILabel alloc] init...];
Later on, you can say
self.nameLabel.hidden = YES;
and it should work.

Answer 3

It's hard to know how that would even compile since the code you show to create nameLabel makes it local to whatever method that's in. Try making nameLabel a property and using self.nameLabel whenever you reference it, either creating it or touching its properties.