Declared Interface errors when building the project - ios

Question

I im fairly new to ios development, and following the tutorial exercise on chapter 4 of the book 'beginning ios5 development' i have run into some compile errors on my code.
here's what my header code .h file looks like
#import <UIKit/UIKit.h>
#interface BIDViewController : UIViewController
#property (strong, nonatomic) IBOutlet UITextField *namefIELD;
#property (strong, nonatomic) IBOutlet UITextField *numberField;
#property (strong, nonatomic) IBOutlet UILabel *sliderLabel;
#property (strong, nonatomic) IBOutlet UISegmentedControl *leftSwitch;
#property (strong, nonatomic) IBOutlet UISegmentedControl *rightSwitch;
#property (strong, nonatomic) IBOutlet UIButton *doSomethingButton;
-(IBAction)textFieldDoneEditing:(id)sender;
//to initialize the 'done' button when editing to confirm you have finished editing/
-(IBAction) backgroundTap:(id)sender;
- (IBAction)sliderChanged:(id)sender;
- (IBAction)switchChanged:(id)sender;
- (IBAction)toggleControls:(id)sender;
- (IBAction)buttonPressed:(id)sender;
#end
and here's my .m code where im facing the error "no visible #interface for 'UISegmentedControl' declares the selector 'setOn:animated;'
#synthesize leftSwitch;
#synthesize rightSwitch;
- (IBAction)switchChanged:(id)sender {
UISwitch *whichSwitch = (UISwitch *)sender;
BOOL setting = whichSwitch.isOn;
[leftSwitch setOn: setting animated: YES]; //the error lies here/
[rightSwitch setO: setting animated: YES]; //the error lies here/
}
- (IBAction)toggleControls:(id)sender {
}
- (IBAction)buttonPressed:(id)sender {
}
#end
the error statement is "no visible #interface for 'UISegmentedControl' declares the selector 'setOn:animated;'
pls help, that would be highly appreciated and voted for :)
#PhilipMills ...here's what i'm talking about, as soon as i click on a leftside or rightside of the segmented control object a break point is automatically made on my delegated header code here
#import <UIKit/UIKit.h>
#import "BIDAppDelegate.h"
int main(int argc, char *argv[])
{
#autoreleasepool {
return UIApplicationMain(argc, argv, nil, NSStringFromClass([BIDAppDelegate class])); //the breakpoint appears here.
}
}

Answer 1

A UISwitch has a setOn:animated: method but a UISegmentedControl does not. I'll guess that you assigned objects to leftSwitch and rightSwitch that are not the kind you intended (or the tutorial intended).