Objective-C NSArray

I'm new to Obj-C and iPhone SDK. The test application I'm stock with is a color switcher containing two buttons ("Back", "Forward") and one text label. The idea is to switch between rainbow colors (background) and setting an appropriate text label in a cyclic manner.

I declared NSArray (which is to contain colors names) in RainbowViewController.h, synthesized it in RainbowViewController.h and I can't add any string into that array.

This is "h" file:

#import <UIKit/UIKit.h>

@interface RainbowViewController : UIViewController {
    IBOutlet UILabel *currentColorTextLabel;
    NSArray *colorsArray;
    NSString *msg;
}

@property (nonatomic, retain) IBOutlet UILabel *currentColorTextLabel;
@property (nonatomic, retain) NSArray *colorsArray;
@property (nonatomic, retain) NSString *msg; 

- (IBAction) pressForwardButton;
- (IBAction) pressBackButton;

@end

This is "m" file:

#import "RainbowViewController.h"
#import <Foundation/Foundation.h>

@implementation RainbowViewController

@synthesize currentColorTextLabel;
@synthesize colorsArray;
@synthesize msg;

int currentArrayIndex = 0;

colorsArray = [[NSArray alloc] init]; //here i get "Initializer element is not constant" error message
[coloursArray addObject:@"Red"]; //here I get "Expected identifier or '(' before '[' token"
[coloursArray addOb开发者_StackOverflowject:@"Orange"];
//etc

- (IBAction) pressForwardButton {
    //here I'm going to increment currentArrayIndex, set an appropriate color, and update a currentColorTextLabel based on currentArrayIndex.
}

- (IBAction) pressBackButton {

}

//auto-genereted code here
@end

I'm new to obj-c as well, but I think you need to initialize the array with objects, or use an NSMutableArray if you want to add objects after it is created.

You have the code that should go in your init method just sitting out in the middle of the file. You can't set instance variables like that.

jasongetsdown is correct. You need to instantiate the NSArray object with the objects it will contain and nil terminated.

@"Red", @"Blue", nil

If you wish to have an array that you can change you need to make it a Mutable Array.

However, you have another problem here. Your property that you are synthesizing and allocating for is an object named colorsArray and you are trying to pass a method to a coloursArray object, two different spellings.