Order of objects in NSSet and NSMutableSet

I wanted to accomplish couple of things with this post. One was to test the SyntaxHighlighter plugin for posting code here and two to explain what I observed in trying to use the NSMutableSet class in the third example of chapter 2 in code I have posted before.

Reading the apple docs on NSMutableSet, it is not clear in what order objects are stored in NSMutableSet or at least what order you will get one if you try to retrieve one. For example if send the anyObject message to an instance of NSMutableSet, do you get the first object or just any random object. The docs are not clear on that. So here is small piece of code that I ran to find out what is returned to us when anyObject is sent as a message.

//  main.m
//  VariousTests
//
//  Created by nata on 11/9/11.
//  Copyright (c) 2011 __MyCompanyName__. All rights reserved.
//

#import <Foundation/Foundation.h>

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

    @autoreleasepool {
        
        NSString *name1, *name2, *name3;
        
        name1 = @"Name1";
        name2 = @"Name2";
        name3 = @"Name3";
        
        //Create a set with string objects
        NSMutableSet *set1 = [NSMutableSet setWithObjects:name1,name2,name3,nil];
        
        //Count them and print them
        NSInteger count = [set1 count];
        NSLog(@"Count of the Set is : %ld", count);
        
        //Get any one of them
        id temp = [set1 anyObject];
        
        //This will print the object contents
        //Notice in the output below it prints the first string
        CFShow(temp);
        
        //remove the second string from set
        [set1 removeObject:name2];
        
        //clear temp
        temp = nil;
        
        //Get one more object and print
        //Notice it prints the same first string object
        temp = [set1 anyObject];
        CFShow(temp);
        
    }
    return 0;
}

Output:

[Switching to process 987 thread 0x0]
2011-11-18 20:34:50.717 VariousTests[987:903] Count of the Set is : 3
Name1
Name1
Program ended with exit code: 0

So it looks like any time you use the anyObject message on a set you will get the first object in the set. And I am hoping my conclusion is right. If anybody has a different analysis please do drop me a note!