How to hide navigation bar in iPhone?

Question

Currently i am working in iPhone app, I have two screen like A and B, A has no navigation bar, but B has navigation bar. so i set like this.

Class A:

Answer 1

Use below line to hide navigationBarin viewWillAppear: method -

-(void)viewWillAppear:(BOOL)animated
{
    self.navigationController.navigationBar.hidden=YES;
}