CODEWITHSUNDEEP
objective-cios6
shizophren
shizophren

Reputation: 21

Fill an array over a class

I have a little (maybe) very simple question that tears my brain appart.

I created a class "ArrayClass":

//  ArrayClass.m


#import "ArrayClass.h"

@implementation ArrayClass{

    NSMutableArray *NameList;

}

@end

Now I want to fill this array over an object of this class in my main file.

I thought this would be right, but unfortunately got no outcome.

//Main File:

//Create an object

ArrayClass *object_bla = [[ArrayClass alloc] init];

So how can I fill my Array with the "object_bla" object?

I can't get access to this array. With normal e.g. int variables I have no problems.

Actually I'm not futher then yesterday. So that's what I'm trying to do.

I need a class, in wich I create an array. This is because I want later fill this array with some userinput.

So I got my Class:

AClass.h

#import <Foundation/Foundation.h>

@interface AClass : NSObject

//Array deklarieren
@property NSMutableArray *WordList;


@end

No in the main file I want to create an object of this class, to get access to the *WordList Array. Later the class gets more stuff, so thats a tryout right now. I'm a C++ developer and very new to objective-c, so appologize my noob questions pls.

Thats what I'm done so far:

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

int main(int argc, const char * argv[])
{

    @autoreleasepool {

    //create object
    AClass *blabla = [[AClass alloc] init];

    //fill array
    [blabla.WordList addObject:@"GünterKörper"];

    //output
    for (int i = 0; i<[blabla.WordList count]; i++){
        NSLog(@"Objekte: %@", [blabla.WordList objectAtIndex:i]);
    }


    }
    return 0;
}

But that gives me nothing. The array is empty. What I'm missing here?

Greets

Upvotes: 0

Views: 115

Answers (2)

Ian L
Ian L

Reputation: 5601

You need to instantiate the array before you can add objects to it. This can be done in various ways:

1 - In the init method of your custom class:

@implementation AClass 

- (id)init {
    self = [super init];
    if (self) {
        _WordList = [[NSMutableArray alloc] init];
    }
    return self
}

// Rest of class implementation...

@end

2 - Use lazy loading by implementing your own property getter in your custom class.

@implementation AClass 

- (NSMutableArray *)WordList {
    if (_WordList == nil) {
        _WordList = [[NSMutableArray alloc] init];
    }
    return _WordList;
}

// Rest of class implementation...

@end

The second is probably preferred as it only allocates the memory when you actually reference the object.

Upvotes: 0

Anoop Vaidya
Anoop Vaidya

Reputation: 46543

You need to create an property for NameList.

@property (strong) NSMutableArray *NameList;

Then in your main file

Create a tempArray in main, fill it with some array, then use:

NSMutableArray *tempArray=[NSMutableArray arrayWithArray:@[@"A",@"B",@"C"]];
[object_bla setNameList:tempArray;

If you want to add one object at a time:

[object_bla.NameList addObject:@"new object"];

Upvotes: 1

Related Questions