Array of buttons returning null - objective-c

Question

I am trying to add the buttons I create to an array and then remove them buttons from the array. My array keeps returning null so I get the feeling my buttons are not even being added to my array?
I am a beginner. I am using Xcode 4.3. Here is my code:
//
// MainViewController.h
// Test-Wards
//
// Created by Dayle Pearson on 5/12/12.
// Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//
#import "FlipsideViewController.h"
#interface MainViewController : UIViewController <FlipsideViewControllerDelegate>
{
/*This stuff creates a timer */
IBOutlet UILabel *opponentsBlue;
NSTimer *timer;
int redBlue;
/*Stuff for making a label creator */
CGPoint startPoint;
int xStuff, yStuff;
/*array for storing wards*/
NSMutableArray *wardArray;
}
#property CGPoint startPoint;
- (IBAction)startRedBlue:(id)sender;
- (IBAction)removeWard:(id)
sender;
- (void)countdown;
#end
//
// MainViewController.m
// Test-Wards
//
// Created by Dayle Pearson on 5/12/12.
// Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//
#import "MainViewController.h"
#interface MainViewController ()
#end
#implementation MainViewController
#synthesize startPoint;
- (void)countdown
{
if (redBlue < 2) {
[timer invalidate];
timer = nil;
}
redBlue -= 1;
opponentsBlue.text = [NSString stringWithFormat:#"%i", redBlue];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *theTouch = [touches anyObject];
startPoint = [theTouch locationInView:self.view];
}
- (IBAction)startRedBlue:(id)sender
{
UIButton *wardButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
wardButton.frame = CGRectMake((startPoint.x - 5), (startPoint.y - 5), 10, 10);
[wardButton setTitle:#"180" forState:UIControlStateNormal];
//add targets and actions
/*[wardButton addTarget:self action:#selector() forControlEvents:<#(UIControlEvents)#>*/
//add to a view
[self.view addSubview:wardButton];
[self->wardArray addObject: wardButton];
NSLog(#"This elemnt = %#", wardArray);
}
- (IBAction)removeWard:(id)sender
{
[self->wardArray removeLastObject];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
#pragma mark - Flipside View
- (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller
{
[self dismissModalViewControllerAnimated:YES];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:#"showAlternate"]) {
[[segue destinationViewController] setDelegate:self];
}
}
#end

Answer 1

You forgot to initialize your wardArray. You should add
wardArray = [NSMutableArray array];
to your designated initializer.
In Objective-C sending messages to nil objects is legal - these messages are simply ignored. That's why you do not see the items that you added.
I also noticed that you add buttons to the view, but you never remove them. To remove the buttons from the screen, change the code as follows:
- (IBAction)removeWard:(id)sender
{
[[self->wardArray lastObject] removeFromSuperview];
[self->wardArray removeLastObject];
}

Answer 2

You have to initialize your array before you can add to it
wardArray = [NSMutableArray array]; // quick and easy
wardArray = [[NSMutableArray alloc] init]; // oldschool
I recommend doing it like so in your method. This will only initialize it once if it doesn't exist so theres no chance of it never being ready to have objects :)
- (IBAction)startRedBlue:(id)sender
{
....
// If wardArray doesn't exist we create it. Otherwise we add our ward to it.
if (!wardArray) {
wardArray = [NSMutableArray array];
} else {
[self->wardArray addObject: wardButton];
}
}
- (IBAction)removeWard:(id)sender
{
UIButton *ward = (UIButton *)sender;
[ward removeFromSuperview]; // Takes it off the screen.
[self->wardArray removeObject:ward]; //Takes it out of the array
}