swift与OC的区别（每日更新）

TwoViewController *v = [[TwoViewController alloc] init]; //这样会把TwoViewController默认关联到TwoViewController.xib上
//等同调用了方法
TwoViewController *v = [[TwoViewController alloc] initWithNibName:@"TwoViewController" bundle:nil];

let v = TwoViewController() //不会关联TwoViewController.xib文件
//一定要指定xib文件
let v = TwoViewController(nibName: "TwoViewController", bundle: nil)