Method to create new objects

[JeroenJK]

Product.h:

Code: (Objective-C)

#import <Foundation/Foundation.h>

@interface Product : NSObject
{
    unsigned int valueOfProducts;
}

-(void) increaseValueOfProducts;
-(void) decreaseValueOfProducts;
-(void) resetValueOfProducts;

@end

Product.m:

Code: (Objective-C)

#import "Product.h"

@implementation Product

-(void) increaseValueOfProducts {
    valueOfProducts += 1;
}

-(void) decreaseValueOfProducts {

    if ( valueOfProducts > 0 ) {
        valueOfProducts -= 1;
    }
}

-(void) resetValueOfProducts {
    valueOfProducts = 0;
}

@end

main.m:

Code: (Objective-C)

#import "Product.h"

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

        Product *sandwich = [[Product alloc] init];
        Product *coke = [[Product alloc] init];
        Product *chips = [[Product alloc] init];
        Product *bread = [[Product alloc] init];

    }
}

Now is my question: Is there any method, or something, that I can add so the user can add objects (so, new products) to the program he wants to keep track of?

I don't remember I have had that in the book, and I don't know what to search for. So I hope someone can help me with this.

Many thanks to anyone responding!