Hide keyboard when click return

#import "ViewController.h"

@interface ViewController ()
- (IBAction)changeGreeting:(id)sender;
@property (weak, nonatomic) IBOutlet UITextField *textFiled;
@property (weak, nonatomic) IBOutlet UILabel *label;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

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

- (IBAction)changeGreeting:(id)sender {
    self.userName = self.textFiled.text;
    NSString *nameString = self.userName;
    if ([nameString length] == 0)
    {
        nameString = @"World";
    }
    NSString *greeting = [[NSString alloc] initWithFormat:@"Hello, %@!", nameString];
    self.label.text = greeting;
}

- (BOOL) textFieldShouldReturn:(UITextField *)theTextField
{
    if (theTextField == self.textFiled)
    {
        [theTextField resignFirstResponder];
    }
    return YES;
}
@end