How to call a View Controller programmatically?

To create a view controller:

UIViewController * vc = [[UIViewController alloc] init];

To call a view controller (must be called from within another viewcontroller):

[self presentViewController:vc animated:YES completion:nil];

For one, use nil rather than null.

Loading a view controller from the storyboard:

NSString * storyboardName = @"MainStoryboard"; 
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:storyboardName bundle: nil];
UIViewController * vc = [storyboard instantiateViewControllerWithIdentifier:@"IDENTIFIER_OF_YOUR_VIEWCONTROLLER"];
[self presentViewController:vc animated:YES completion:nil];

Identifier of your view controller is either equal to the class name of your view controller, or a Storyboard ID that you can assign in the identity inspector of your storyboard.

You need to instantiate the view controller from the storyboard and then show it:

ViewControllerInfo* infoController = [self.storyboard instantiateViewControllerWithIdentifier:@"ViewControllerInfo"];
[self.navigationController pushViewController:infoController animated:YES];

This example assumes that you have a navigation controller in order to return to the previous view. You can of course also use presentViewController:animated:completion:. The main point is to have your storyboard instantiate your target view controller using the target view controller's ID.

Swift

This gets a view controller from the storyboard and presents it.

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let secondViewController = storyboard.instantiateViewController(withIdentifier: "secondViewControllerId") as! SecondViewController
self.present(secondViewController, animated: true, completion: nil)

Change the storyboard name, view controller name, and view controller id as appropriate.

You can call ViewController this way, If you want with NavigationController

1.In current Screen : Load new screen

VerifyExpViewController *addProjectViewController = [[VerifyExpViewController alloc] init];
[self.navigationController pushViewController:addProjectViewController animated:YES];

2.1 In Loaded View : add below in .h file

@interface VerifyExpViewController : UIViewController <UINavigationControllerDelegate>

2.2 In Loaded View : add below in .m file

  @implementation VerifyExpViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.navigationController.delegate = self;
    [self setNavigationBar];
}
-(void)setNavigationBar
{
    self.navigationController.navigationBar.backgroundColor = [UIColor clearColor];
    self.navigationController.navigationBar.translucent = YES;
    [self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"B_topbar.png"] forBarMetrics:UIBarMetricsDefault];
    self.navigationController.navigationBar.titleTextAttributes = @{NSForegroundColorAttributeName: [UIColor whiteColor]};
    self.navigationItem.hidesBackButton = YES;
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"Btn_topback.png"] style:UIBarButtonItemStylePlain target:self action:@selector(onBackButtonTap:)];
    self.navigationItem.leftBarButtonItem.tintColor = [UIColor lightGrayColor];
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"Save.png"] style:UIBarButtonItemStylePlain target:self action:@selector(onSaveButtonTap:)];
    self.navigationItem.rightBarButtonItem.tintColor = [UIColor lightGrayColor];
}

-(void)onBackButtonTap:(id)sender
{
    [self.navigationController popViewControllerAnimated:YES];
}
-(IBAction)onSaveButtonTap:(id)sender
{
    //todo for save button
}

@end

Hope this will be useful for someone there :)

There's 2 ways you can do this:

1, Create a segue to your ViewController in your Storyboard as explained in my answer here: How to perform a segue that is not related to user input in iOS 5?

2, Give your ViewController and identifier and call it using the code in my answer here: Call storyboard scene programmatically (without needing segue)?