How to fix the warning of "Autosynthesized property 'myVar' will use synthesized instance variable '_myVar', not existing instance variable 'myVar' "?

Question

I declare my .h file like this:

#import <UIKit/UIKit.h>

@interface NavigationTripViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource>{
    NSArray *questionTitleTrip;
    NSArray *questionDescTrip;
    NSMutableArray *answerTrip;
    NSMutableArray *pickerChoices;
    int questionInt;
    int totalInt;
    IBOutlet UILabel *questionNum;
    IBOutlet UILabel *questionTotalNum;
    IBOutlet UILabel *recordType;
    IBOutlet UITextView *questionDes;
    IBOutlet UIView *answerView;
    IBOutlet UIButton *preButton;
    IBOutlet UIButton *nextButton;
    UITextField *text;
    UIPickerView *picker;

}
@property (retain, nonatomic) NSArray *questionTitleTrip;
@property (retain, nonatomic) NSArray *questionDescTrip;
@property (retain, nonatomic) NSMutableArray *answerTrip;
@property (retain, nonatomic) NSMutableArray *pickerChoices;
@property (retain, nonatomic) IBOutlet UILabel *questionNum;
@property (retain, nonatomic) IBOutlet UILabel *questionTotalNum;
@property (retain, nonatomic) IBOutlet UILabel *recordType;
@property (retain, nonatomic) IBOutlet UITextView *questionDes;
@property (retain, nonatomic) IBOutlet UIView *answerView;
@property (retain, nonatomic) IBOutlet UIButton *preButton;
@property (retain, nonatomic) IBOutlet UIButton *nextButton;
@property (retain, nonatomic) UITextField *text;
@property (retain, nonatomic) UIPickerView *picker;
-(IBAction)clickPre;
-(IBAction)clickNext;
@end

And my .m file here like this:

#import "NavigationTripViewController.h"
#import <QuartzCore/QuartzCore.h>

@interface NavigationTripViewController ()

@end

@implementation NavigationTripViewController

@synthesize questionTitleTrip,questionDescTrip,answerTripl,pickerChoices,questionNum,questionTotalNum,recordType,questionDes,answerView,preButton,nextButton,text,picker;

All my variables in the @synthesize receive the warnings:

Autosynthesized property 'myVar' will use synthesized instance variable '_myVar', not existing instance variable 'myVar'

Also, the variables and class names used in viewDidLoad don't display in colors, just show in black color. In other view controllers, there are no warnings like this. How to fix these problems?

Answer 1

Edit: Basically for all intents and purposes you should be building on a new enough XCode to use the new behavior, in that solution you typically will just remove the ivar from the @interface block in the .h file... If for some reason you do need to access an ivar directly you can now declare it in the @implementation block... and use @synthesize var or @synthesize var=_var

OGPost:

to make that go away you can go all new school and drop the iVar, or you can go all old school and add an @synthesize someIvar in your @implementation block.