iOS Novice - viewDidLoad

Question

I'm going through the Apple Start Developing Guide and I have encountered an error in the demo app.

The code is as follows:

#import "XYZToDoListViewController.h"
#import "XYZToDoItem.h"

@interface XYZToDoListViewController ()

@property NSMutableArray *toDoItems;
-(void)viewDidLoad{
    [super viewDidLoad];
    self.toDoItems = [[NSMutableArray alloc]init];
    [self loadInitialData];
}

@end

@implementation XYZToDoListViewController
-(void)loadInitialData{
    XYZToDoItem *item1 = [[XYZToDoItem alloc]init];
    item1.itemName = @"Buy Milk";
    [self.toDoItems addObject:item1];

    XYZToDoItem *item2 = [[XYZToDoItem alloc]init];
    item2.itemName = @"Go Shopping";
    [self.toDoItems addObject:item2];

    XYZToDoItem *item3 = [[XYZToDoItem alloc]init];
    item3.itemName = @"Wake Up";
    [self.toDoItems addObject:item3];
}
- (IBAction)unwindToList:(UIStoryboardSegue *)segue
{

}


- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Uncomment the following line to preserve selection between presentations.
    // self.clearsSelectionOnViewWillAppear = NO;

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    return [self.toDoItems count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"ListPrototypeCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

    // Configure the cell...
    XYZToDoItem *toDoItem = [self.toDoItems objectAtIndex:indexPath.row];
    cell.textLabel.text = toDoItem.itemName;
    return cell;
}

/*
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the specified item to be editable.
    return YES;
}
*/

/*
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        // Delete the row from the data source
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
    }   
    else if (editingStyle == UITableViewCellEditingStyleInsert) {
        // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
    }   
}
*/

/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
*/

/*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the item to be re-orderable.
    return YES;
}
*/

/*
#pragma mark - Navigation

// In a story board-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}

 */
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{

}
@end

On building it comes up with an error saying it expected ; after viewDidLoad. I have googled this to see if I can figure out why but can't seem to.

Answer 1

The below property should be in .h file. Because in .h file we need to declare the method so property will declare the method which should be in .h file

 @property NSMutableArray *toDoItems;

And below will be in .m file because in .m file we need to define the method.

- (void)viewDidLoad
 {
[super viewDidLoad];

self.toDoItems = [[NSMutableArray alloc] init];
  [self loadInitialData];
    }

Answer 2

It looks like you might either have the property:

@property NSMutableArray *toDoItems;

In the implementation file (.m) or the method:

-(void)viewDidLoad{
    ...
}

In the header file (.h).

In addition you'll need an @implementation or @interface. Maybe you should update your question with the full code from the file.

Answer 3

put this in your .h file

 @interface className : Class that you inherit

 @property NSMutableArray *toDoItems;

 @end

of course, you'd need to replace className with your name for the class, and the 'Class that you inherit' with the super classes such as NSObject, UIViewController, UIView, or any other class.

and put this in your .m file

@implementation className

-(void)viewDidLoad{
    [super viewDidLoad];
    self.toDoItems = [[NSMutableArray alloc]init];
    [self loadInitialData]; 
}

@end

that should help.

Hope it helps :)