Question

Okay, so I’m pretty new to xcode but I cannot find something specific to this issue anywhere. So I declare the array and instantiate it in the following files:

    //xmlToUrl.h

#import <Foundation/Foundation.h>


@interface xmlToUrl : NSObject {
    NSMutableArray *field;
    NSMutableArray *name;
}
@property(nonatomic, retain)NSMutableArray *field;
@property(nonatomic, retain)NSMutableArray *name;

@end

and

    //xmlToUrl.m

#import "xmlToUrl.h"

@implementation xmlToUrl
@synthesize field;
@synthesize name;

-(void)dealloc
{
    [field release];
    [name release];
    [super dealloc];    
}

@end

So this is where I am confused. I don’t know how to correctly “alloc” or “init” the mutable arrays, nor how to handle the add/remove operations from another file which inherits xmlToUrl.h.

The code (in the other file) as I have it now just prints null. Its listed below. What am I doing wrong?!?

//nodeContent is just a NSMutableString

[xmlToUrlObject.name addObject:nodeContent];
        NSLog(@"xml Name = %@", xmlToUrlObject.name);

       //I omitted all the operational code here but if I NSLog nodeContent it prints the correct values

[xmlToUrlObject.field addObject:nodeContent];
        NSLog(@"xml Field = %@", xmlToUrlObject.field);

Answer 1

You need an init function in your implementation file, it would look similar to the following

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

Then whenever you create an instance of your xmlToUrl class via [[xmlToUrl alloc] init] you will have an instance of your class that has already initialized your two NSMutableArrays