Thread1：EXC_BAD_ACCESS（代码= 1，地址= 0x5146a345）

Question

i am trying to implement calendar. i have one label for year and two buttons for incrementing and decrementing year from calendar. i am getting this exception (Thread1: EXC_BAD_ACCESS(code=1,address=0x5146a345)) while clicking button(increment or decrement)my requirement is if i click right button my year should increase as well as if i click left button my year should decrease. my exception line is date = [cal dateByAddingUnit:NSCalendarUnitYear value:1 toDate:date options:0]; could you please help to resolve this issue. this is my code

   - (void)viewDidLoad
    {
        [super viewDidLoad];

        date = [NSDate date];
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setDateFormat:@"YYYY"];
        NSString *stringFromDate = [formatter stringFromDate:date];
        yar1.text=stringFromDate;

     }
    - (IBAction)right:(id)sender {

        NSCalendar *cal = [NSCalendar currentCalendar];

        date = [cal dateByAddingUnit:NSCalendarUnitYear value:1 toDate:date options:0];
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setDateFormat:@"YYYY"];
        NSString *stringFromDate = [formatter stringFromDate:date];
        yar1.text=stringFromDate;

       }
 - (IBAction)left:(id)sender {

        NSCalendar *cal = [NSCalendar currentCalendar];

        date = [cal dateByAddingUnit:NSCalendarUnitYear value:1 toDate:date options:0];
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setDateFormat:@"YYYY"];
        NSString *stringFromDate = [formatter stringFromDate:date];
        yar1.text=stringFromDate;

       }

Answer 1

You need a date component to change the date like this,

-(NSDate *)offsetYear:(int)numOfYears date:(NSDate*)date 
{
NSDateComponents *offsetComponents = [[NSDateComponents alloc] init];
[offsetComponents setYear:numOfYears];

return [[NSCalendar currentCalendar] dateByAddingComponents:offsetComponents
                              toDate:date options:0]; }

Pass the offset as 1 for right and -1 for left