Question

I need to pre-populate and save an array in NSUserDefaults so that downstream methods can read and write to ten values stored there. I’ve constructed this workable solution, but is there a better way of doing this?

Any insight is appreciated!
lq

NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *myArray = [[NSMutableArray alloc] init];

// Set the array with ten Zero Value placeholders

for (NSUInteger i = 0; i < 10; ++i) {                                               
    [myArray addObject:[NSNumber numberWithInt:0]];
}

[userDefaults setObject:myArray forKey:@"someKeyName"];
[myArray release];

Later methods call this array like this:

- (void)doSomethingUseful {

    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];

    NSMutableArray *someUsefulArray = [[NSMutableArray alloc] initWithArray:[userDefaults objectForKey:@"someKeyName"]];

    // read some values, write some values: int someInt = [someUsefulArray objectAtIndex:3]; // etc.
    // store array values back to NSUserDefaults . . .

    // IS THERE A WAY TO READ AND WRITE DIRECTLY TO INDEX 3 of the NSUserDefaults array instead???

    [someUsefulArray release]
}

Answer 1

I’ve actually done the same thing in a shipping application. Sure, it doesn’t feel elegant, but it does the job.