Objective-C NSMutableArray only returning one item - ios

Question

I am trying to print out a list of objects in my NSMutableArray via NSLog, but for some reason, it is appearing to be null. Basically, I have a to-do list that when the user enters a new string to add to the tableview, it will also add that item to the NSArray so I can save it to the device.
AddToDoItemViewController.m
#import "AddToDoItemViewController.h"
#import "ToDoItem.h"
#interface AddToDoItemViewController ()
#property (weak, nonatomic) IBOutlet UITextField *textField;
#property (weak, nonatomic) IBOutlet UIBarButtonItem *saveButton;
#end
#implementation AddToDoItemViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
self.toDoItem.itemList = [[NSMutableArray alloc] init];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Navigation
// In a storyboard-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.
if (sender != self.saveButton) return;
if (self.textField.text.length > 0) {
self.toDoItem = [[ToDoItem alloc] init];
self.toDoItem.itemName = self.textField.text;
self.toDoItem.completed = NO;
NSLog(#"Trying to add to array: %#", self.toDoItem.itemName);
[self.toDoItem.itemList addObject:self.toDoItem.itemName];
NSLog(#"Array contents: %#", self.toDoItem.itemList);
}
}
#end
AddToDoItemViewController.h
#import <UIKit/UIKit.h>
#import "ToDoItem.h"
#interface AddToDoItemViewController : UIViewController
#property ToDoItem *toDoItem;
#end
ToDoItem.h
#import <Foundation/Foundation.h>
#interface ToDoItem : NSObject
#property NSString *itemName;
#property BOOL completed;
#property (readonly) NSDate *creationDate;
#property NSMutableArray *itemList;
#end
Now from my AddToDoItem.m file, when I use NSLog to try to output the Array I get this:
2016-02-24 01:04:49.668 ToDoList[4025:249117] Trying to add to array: ok
2016-02-24 01:04:49.669 ToDoList[4025:249117] Array contents: (null)
**** The 'ok' was the text I entered *****

Answer 1

You did not initialise the array before adding to it, add self.toDoItem.itemList = [NSMutableArray new];
Edit:
oh i see you added self.toDoItem.itemList = [[NSMutableArray alloc] init]; in the viewDidLoad, but this is not the right place to put it, it should be after self.toDoItem = [[ToDoItem alloc] init]; or inside the init method of ToDoItem

Answer 2

First, you need create an init method at ToDoItem.m
- (id)init {
self = [super init];
if (self) {
// Any custom setup work goes here
self.itemList = [[NSMutableArray alloc] init];
}
return self;
}
then run your project again.

Answer 3

You are initialising the Array( itemList ) before ToDoItem is initialised, so initialised array remains nil. So, it cannot store any object.
Modify code as below,
self.toDoItem = [[ToDoItem alloc] init];
self.toDoItem.itemList = [[NSMutableArray alloc] init];
you can add above lines of code either at viewDidLoad or at Segue Method
hope it helps you.