class MainViewController < UIViewController def viewDidLoad super @label = UILabel.new @label.frame = [[10, 10], [320, 20]] @label.font = UIFont.boldSystemFontOfSize(16) @label.text = "Hello World" view.backgroundColor = UIColor.whiteColor view.addSubview(@label) # for navigation bar navigationItem.title = "Navigation Title" # for tab bar self.tabBarItem = UITabBarItem.alloc.initWithTitle("Tab1",