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Just wondering the best way to create a manual array, without using NSMutalbleArray, I have being researching best possible solutions but without an elegant answer, what do you think, in Objective C what's the best way to create an NSMutableArray style object from scratch? with a FIFO queue as the final solution, even a basic array structure would be a great hint! thanks, If you have the need to bound it, why not just use a normal array and manage push and pop indeces? – NG. Oct 29, 2012 at 20:39

Categories on NSMutableArray is the easiest way IMO. I have a category for stacks (LIFO) and queues (FIFO)

Header

#import <Foundation/Foundation.h>
@interface NSMutableArray (QueueStack)
-(id)queuePop;
-(void)queuePush:(id)obj;
-(id)stackPop;
-(void)stackPush:(id)obj;
Implementation
#import "NSMutableArray+QueueStack.h"
@implementation NSMutableArray (QueueStack)
// Queues are first-in-first-out, so we remove objects from the head
-(id)queuePop {
  @synchronized(self)
    if ([self count] == 0) {
        return nil;
    id queueObject = [[[self objectAtIndex:0] retain] autorelease];
    [self removeObjectAtIndex:0];
    return queueObject;
// Add to the tail of the queue
-(void)queuePush:(id)anObject {
  @synchronized(self)
    [self addObject:anObject];
//Stacks are last-in-first-out.
-(id)stackPop {
  @synchronized(self)
    id lastObject = [[[self lastObject] retain] autorelease];
    if (lastObject)
        [self removeLastObject];
    return lastObject;
-(void)stackPush:(id)obj {
  @synchronized(self)
    [self addObject: obj];
To Make and use a queue:
NSMutableArray *queue = [NSMutableArray array];
//Put an item in the queue
[queue queuePush:myObj];
//Retrieve an item, (this will be the first one)
MyCoolObject *myObject = [queue queuePop];
if (mutArr.count == 5) {
        for (int j = 0; j < 4; j++) {
            [mutArr exchangeObjectAtIndex:j withObjectAtIndex:j+1];
        [mutArr removeObjectAtIndex:4];
        [mutArr addObject:mutDict];
    }else{
        [mutArr addObject:mutDict];
Even though I don't understand the problem with an NSMutableArray, here's a way you could implement a queue using a doubly linked list (Hopefully I got it right, I'm kinda tired ;)):
Note: I'm assuming usage of ARC.
//Node.h
@interface Node : NSObject
@property (strong)id value;
@property (strong)Node *previous;
@property (strong)Node *next;
//Node.m
@implementation
/Queue.h
@interface Queue : NSObject
- (void)enqueue:(id)objectToEnqueue;
- (id)dequeue;
//Queue.m
@interface Queue ()
    Node *start;
@implementation
- (void)enqueue:(id)objectToEnqueue
    Node *node = [Node new];
    node.value = objectToEnqueue;
    if (nil == start)
        node.previous = node;
        node.next = node;
        start = node;
        node.previous = start.previous;
        node.next = start;
        start.previous = node;
        start = node;
- (id)dequeue
    if (nil == start)
        return nil;
    Node *node = start.previous;
    start.previous = start.previous.previous;
    start.previous.next = start;
    id objectToDequeue = node.value;
    return objectToDequeue;
If you're looking for a way to do that in pure C, maybe this will help you: 
C PROGRAM TO IMPLEMENT A QUEUE
        
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