Is there a literal syntax for mutable collections?

I know I can create an NSArray with @[@"foo", @"bar"] or an NSDictionary with @{@0 : @"foo", @1 : @"bar"}.

Is there a literal syntax for creating an NSMutableArray or an NSMutableDictionary?

Objective-C Simplest way to create comma separated string from an array of objects

So I have a nsmutablearray with a bunch of objects in it. I want to create a comma separated string of the id value of each object.

Add an object to the beginning of an NSMutableArray?

Is there an efficient way to add an object to start of an NSMutableArray? I am looking for a good double ended queue in objective C would work as well.

Adding an object at a specific index of an NSMutableArray

How can an object be added at a specific index of an NSMutableArray?

How is an object added to the front of the array?

Disadvantage of using NSMutableArray vs NSArray?

I'm using an array to store cached objects loaded from a database in my iPhone app, and was wondering: are there any significant disadvantages to using NSMutableArray that I should know of?

edit: I know that NSMutableArray can be modified, but I'm looking for specific reasons (performance, etc..) why one would use NSArray instead. I assume there would be a performance difference, but I have no idea whether it's significant or not.

How to store CGRect values in NSMutableArray?

How would I store CGRect objects in a NSMutableArray, and then later retrieve them?

How to return an NSMutableArray from an NSSet

I'm able to put the contents of an NSSet into an NSMutableArray like this:

NSMutableArray *array = [set allObjects];

The compiler complains though because [set allObjects] returns an NSArray not an NSMutableArray. How should this be fixed?

NSMutableArray addObject: -[__NSArrayI addObject:]: unrecognized selector sent to instance

I have tried to initialize my NSMutableArray 100 ways from Sunday, and NOTHING is working for me. I tried setting it equal to a newly allocated and initialized NSMutableArray, just allocating, initializing the variable by itself, every combination I could think of and always the same result.

Here's the code:

Object.h

NSMutableArray *array;

@property (copy) NSMutableArray *array;

Object.m

@synthesize array;

if ( self.array ) {
    [self.array addObject:anObject];
}
else {
    self.array = [NSMutableArray arrayWithObjects:anObject, nil];
}

NOTE: In debug "anObject" is NOT nil at time of execution...

I have tested anObject and it isThe initialization works just fine, but I keep getting the error below when I try to addObject: to self.array.

2010-07-10 11:52:55.499 MyApp[4347:1807] -[__NSArrayI addObject:]: unrecognized selector sent to instance 0x184480

2010-07-10 11:52:55.508 MyApp[4347:1807] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayI addObject:]: unrecognized selector sent to instance 0x184480'

Does anyone have any idea what's going wrong?

Copy & mutableCopy?

What is the difference between the "copy" & "mutableCopy"?

EDIT_001:

My original post was a bit of a mess, partly due to a lack of understanding and partly due to a bit of pilot error on my part. Here is my attempt to better explain how "copy" & "mutableCopy" work.

// ** NSArray **
NSArray *myArray_imu = [NSArray  arrayWithObjects:@"abc", @"def", nil];

// No copy, increments retain count, result is immutable
NSArray *myArray_imuCopy = [myArray_imu copy];

// Copys object, result is mutable 
NSArray *myArray_imuMuta = [myArray_imu mutableCopy];

[myArray_imuCopy release];
[myArray_imuMuta release];

.

// ** NSMutableArray **
NSMutableArray *myArray_mut = [NSMutableArray arrayWithObjects:@"A", @"B", nil];

// Copys object, result is immutable
NSMutableArray *myArray_mutCopy = [myArray_mut copy];

// Copys object, result is mutable
NSMutableArray *myArray_mutMuta = [myArray_mut mutableCopy];

[myArray_mutCopy release];
[myArray_mutMuta release];

EDIT_002:

1. mutableCopy always returns a mutable result.
2. copy always returns an immutable result.

thank you for all the answers, comments ... much appreciated.

gary

Difference between NSArray and NSMutableArray

What is the difference b/w NSArray and NSMutableArray?

NSMutableArray addObject not working

I have declared an NSMutableArray *categories in my view controller .h file, and declared a property for it.

In the parser:foundCharacters: method of the NSXMLParser delegate in my .m file, I have this code:

-(void)parser:(NSXMLParser *) parser foundCharacters:(NSString *)string  
{  
    if (elementFound)  
    {  
        element = string;  
        [self.categories addObject:element];  
    }  
}

But when I hover over the [self.categories addObject:element] line after stepping into it in debug mode, XCode tells me the size is 0x0, 0 objects. There are 3 elements in my XML file so 3 items should be in the array.

I'm missing something really obvious and I can't figure out what.

UITableView, how do I know what Section during cellForRowAtIndexPath?

I have a UITableView displaying a list of Cities. I want to separate them by State. I can't seem to figure out how to get it to pick the right items out of my Array. If Section 1 (Arizona) has 2 Cities and Section 2 (California) has 2 Cities, during cellForRowAtIndexPath, Section 2, City 1 has an index of 0, even though it's the 3rd item in my array. I thought about just turning my City Array into a State Array, where each item holds an Array of Cities, but I still don't know what section I'm on and therefore don't know which City Array under the States Array I would need to access.

Any help would be appreciated.

How do I reverse the order of objects in an NSMutableArray? [duplicate]

I'm trying to achieve something like this

NSMutableArray *myArray = [NSMutableArray arrayWithObjects:@"A",@"B",@"C", nil];
NSLog(@"Array: %@", myArray);
//logs A, B, C.

//reverse code here

 NSLog(@"Array: %@", myArray);
//logs C, B, A

The code isn't exact, just a demo. But you get the idea.

Any way to do this?

UIActivityViewController - Email and Twitter sharing

I recently started working with UIActivity to share my app to the world, but I have few problems. First, I didn't find how to set the subject of my email. Is there any way? Second, when I set the body text of my email, there is a extra "enter" (first line of the email is blank and my text starts at the second line). Here's the code:

 NSMutableArray *array = [[NSMutableArray alloc] initWithObjects: @"Test", nil];

    UIActivityViewController *activityViewController = [[UIActivityViewController alloc]
                                   initWithActivityItems:array applicationActivities:nil];

And in the email, it shows that:

"

Test "

Third: is there a way to know which sharing method has been selected? Because I want to include a hashtag in my post when the user shares on twitter, but now it gets integrated in the email also, which obviously doesn't make sense.

Thanks!

How do I convert NSMutableArray to NSArray?

How do I convert NSMutableArray to NSArray in objective-c?