#import "VCExampleViewController.h"
//---import the header file for the view controller---
#import "SecondViewController.h"
 
@implementation VCExampleViewController
SecondViewController *secondViewController;
//---add the view of the second view controller to the current view---
-(IBAction) displayView:(id) sender{
    secondViewController = [[SecondViewController alloc] 
                                    initWithNibName:@"SecondView" 
                                    bundle:nil];
    [self.view addSubview:secondViewController.view];
}
- (void)dealloc {
    //---release the memory used by the view controller---
    [secondViewController release];
    [super dealloc];
} 
@end

Link to a new view controller from the first view controller

Objective C