Question

Currently attempting to save an array that is populated according to which cells in a UITableView are chosen and saving this array in an instance of a seperate object. I am getting the array to populate just fine, however, my save method, which is an IBAction that is invoked by clicking on a Bar Button doesn’t seem to be working. Here is some code:

-(IBAction)saveWorkout:(id)sender {
    Workouts *new = [[Workouts alloc] init];
    [new addNewWorkout:customWorkout];

    [customWorkout removeAllObjects];
}

This code is from the first class.

And here is the code for my addNewWorkouts method in the Workouts class:

-(void)addNewWorkout:(NSMutableArray*)array {
    NSMutableArray *temp = [[NSMutableArray alloc] init];
    temp = array;

    self.workoutList = temp;

    [temp release];

}

Here is my “Workout.h”

#import <Foundation/Foundation.h>


@interface Workouts : NSObject {
    NSString *workoutName;
    NSMutableArray *workoutList;
    NSString *description;
    int *reps;
    int *weights;
    int *sets;
}
@property (nonatomic, retain) NSString *workoutName;
@property (nonatomic, retain ) NSString *description;
@property (nonatomic, retain) NSMutableArray *workoutList;

-(void)addNewWorkout:(NSMutableArray*)array;

@end

Before running this code, I get a Warning from Xcode saying that ‘Workouts may not respond to ‘addNewWorkouts.’

Anyone know what is causing this error? Once I build & run, I click on the Save button and the app crashes with a unrecognized selector sent to instance 0x3b04410 error.

Answer 1

You call [new addNewWorkouts:customWorkout]
when the method’s selector is addNewWorkout: (note that there is no plural in the method name)

This will make a bad method call and result in a crash.

Also, there is a problem with the memory management of the addNewWorkout method.

1- NSMutableArray *temp = [[NSMutableArray alloc] init];
2- temp = array;
3- self.workoutList = temp;
4- [temp release];

You allocate a new NSMutableArray on line 1, then lose its reference on line 2 when you replace its pointer by ‘array’. The allocation you just made is lost and the program will leak.

Then, on line 4, you send a release message to ‘temp’ which actually points to ‘array’, resulting in the release of the parameter that you received and not the temporary object.

Is there a reason whny you create a temporary array? You can just assign the property and make the property copy or retain it, depending on your needs.