nsmutablearray

lately I work much with arrays and I'm wonder.. what's diffrences between those two lines. NSArray *array = [NSArray arrayWithArray:someArray]; and NSArray *array = [someArray copy]; Which of it is faster? What in case we have NSMutableArray and mutableCopy ? Which of it is faster? Don't worry about it. Premature optimization. The main difference: the first approach results in an autoreleased "copy" that you don't own and don't have to release, while you do own the object created on the second line. Both arrays will be immutable, by the way. In addition to the other answers, also note, that

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I've been programming C/C++ for 20 years but I'm new to objective-c and Coco and have some questions about the performance of NSMutableArray and NSArray. I need an container much like the stl list container, but coco doesn't seem to have one and inserting and removing elements from the middle of MSMutableArray seems slow, but treating it like a stl vector isn't that fast either. Also, MSMutableArray seems to only store Objects, so keep tracking of a simple data type line int or float incurs additional overhead of creating Objects

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I created an "SDMutableGrid" class so that I could use a grid. It's just a child of NSMutableArray that contains a number for arrays equal to the number of rows in the grid. Currently, the program quits before it really starts and it appears that it is because the methods defined for NSMutableArray somehow do not apply to SDMutableGrid, anyone know why? Here is the .h : #import <Foundation/Foundation.h> #import "SDDimensions.h" @interface SDMutableGrid : NSMutableArray { SDDimensions dimensions; } @property (nonatomic) SDDimensions

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: i use this code to check if any objects exist in my NSMutableArray if yes i remove them all but it crashes although there are objects why? if([NSMutableArray1 count]==1) { [poemoptionslist removeAllObjects]; } if ([NSMutableArray1 count]==0) { [poemoptionslist addObject: final1]; } CONSOLE OUTPUT 2010-10-18 03:42:13.166 app1[33398:207] * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[__NSCFArray removeObjectAtIndex:]: mutating method sent to immutable object' * Call stack at first throw: ( 0

I want to get all the filenames in my application's documents folder, and place them in an NSMutableArray . Nothing more, nothing less. There is a convenient method in NSFileManager : NSFileManager *fileManager = [[NSFileManager alloc] init]; NSArray *files = [fileManager contentsOfDirectoryAtPath:documentsDirectory error:nil]; ... [fileManager release]; As of ARC you can of course drop the release statement. 来源： https://stackoverflow.com/questions/7064190/iphone-sdk-xcode-how-to-get-all-the-filenames-in-the-documents-dir

I have a custom object like: #import <Foundation/Foundation.h> @interface Store : NSObject{ NSString *name; NSString *address; } @property (nonatomic, retain) NSString *name; @property (nonatomic, retain) NSString *address; @end I have an array of NSMutableArray (storeArray) containing Store objects: store1 = [[Store alloc] init]; store1.name = @"Walmart"; store1.address = @"walmart address here.."; store2 = [[Store alloc] init]; store2.name = @"Target"; store2.address = @"Target address here.."; store3 = [[Store alloc] init]; store3.name = @"Apple Store"; store3.address = @"Apple store

I'm storing a bunch of data in a .plist file (in the application documents folder), and it's structured like this: Dictionary { "description" = "String Value", "sections" = Array ( Array ( Number, ... Number ), Array ( Number, ... Number ) ), "items" = Array ( Array ( Number, ... Number ), Array ( Number, ... Number ) ) } If I just retrieve it with NSMutableDictionary *d = [[NSMutableDictionary alloc] initWithContentsOfFile:plistFile] I won't be able to replace the number objects, correct? So I'm recursing through the data right now and forming a mutable version of the whole thing, and it

In Objective C I'm using a NSMutableArray instance from various thread and I'm using @synchronized to make it thread safe. currently all my acces to this array are protected with a @synchronized block, even objectAtIndex: method. Nevertheless I wonder which methods call really need to be protected with @synchronized. do I need to protect read access ? What would happens if 'ObjectAtIndex' is not protected and called at the same time that 'removeObject' ? If all methods are protected by a @synchronized what about performance? (I'writing a tcp/udp game server and really don't want to overprotect