nsmutablearray

I am getting an error 'Attempt to mutate immutable object with appendString:' and my code is NSMutableString *resultString= [[NSMutableString alloc]init]; for (NSMutableString *s in self.ArrayValue) { [resultString appendString:s]; NSLog(resultString); } ArrayValue is NSMutableArray. I am not able to understand where is the problem thank you in advance As posted, the code you have will not give you the error you describe. Probably, somewhere between allocating resultString and the for loop, you are overwriting it with a normal NSSring. Just do have like this: It works for me... NSMutableString

I'm absolutely new to iOS Dev. I started out with the really helpful tutorial on Apple dev website So i made the simple To-Do List application, as per instructions. The App: It's a simple to-do list. It has a view, with a single text-field, which takes in an input, which then appends that input to the table-list view. the table list view is my "TO-Do List" which is generated from a NSMutableArray. The Problem: Whenever i quit and relaunch the application, my List disappears. The Question: I need a way to persist the NSMutableArray *ToDoList which stores my list. So is it possible to persist

I have a little problem, and I need help. I want to loop through a multidimensional array, and every time I find a value for a key ex."name" that is equal to ex. "Hello". I want to copy that array object into another array. How do I do that? I assume you have a 2-dimensional array and since I don't know how your objects within the array look like I take the id type and the method valueForKey : NSMutableArray *tmp = [[NSMutableArray alloc] init]; for(NSArray *dim1Array in yourMultidimensionalArray) { for(id obj in dim1Array) { if([[obj valueForKey:@"name"] isEqualToString:@"Hello"]) { [tmp

一、NSArray的基本介绍： NSArray是OC语言中的数组类，可以存放多种类型的数据。 二、NSArray的初始化： //只有一个数据的数组 NSArray *arr1 = [NSArray arrayWithObject:@"1"]; NSArray *arr2 = [NSArray arrayWithObjects:@"2",@"3",@"4",nil]; //用数组生成另一个数组 NSArray *arr3 = [NSArray arrayWithArray:arr2]; //多个数据的数组初始化（最常用） NSArray *arr4 = @[ arr1, arr2, arr3 ]; for (int i = 0; i < 3; i++) { NSLog(@"arr%d - %@",i,arr4[i]); } 三、NSArray的常见用法： //初始化字符串arr NSArray *arr = @[@"1",@"2",@"3",@"a",@"b",@"c",@"你好",@"我好",@"他好"]; //arr.count - 获取数组中元素的个数 NSLog(@"arrr - count - %lu",(unsigned long)arr.count); //objectAtIndex - 获得某个位置的元素 NSLog(@"arr - 2 - %@",[arr

I'm working on a homework app that uses custom Assignment objects for each assignment. I am trying to store an NSMutableArray (casted to an NSArray via initWithArray:) in standardUserDefaults but I'm having trouble with saving and reloading the array. I have a table view from which you can choose to add a new assignment (which loads NewAssignmentViewController). When you save the assignment, it is pushed back to an array in AssigmentsViewController. And then you call it every time you load the UITableView which shows the assignments. Here is the relating code: -(void)saveToUserDefaults:

i want to show my email headers in a UITableView when inbox button clicked, my email headers is stored in an NSMutable Array, -(IBAction)buttonInbox:(id)sender{ NSLog(@"Inbox Button Clicked %@",buttonInbox); [self select:@"INBOX"]; NSArray *lines = [self sendCommand:@"fetch 1:* (body[header.fields (from subject date)])"]; //NSMutableArray *emaiArray= [[NSMutableArray alloc] init]; NSMutableString *totalEmail= [NSMutableString stringWithString:@""]; int counter = 0; int i =0; NSRange tmp; for(i=0;i<[lines count];i++) { NSString *line = [lines objectAtIndex:i]; //NSLog(@" Burda %@" ,line); tmp =

This question already has answers here : Why NSMutableDictionary don't want write to file? (2 answers) Closed 5 years ago . I looked around other similar questions about this but nothing really worked. I managed to write only one pair (object / key) of the dictionary (e.g.: setObject:itemProperties[0] forKey[0]) on my Plist. But I would like all the objets and keys to be added. I didn't managed so far (return the error). Any help? // Path to Documents Folder NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths

For some reason this sample code works: NSArray *immutable = @[ @"a", @"b", @"c" ]; NSMutableArray *mutable = (__bridge id)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (__bridge CFArrayRef)immutable, kCFPropertyListMutableContainers); and this code produces nil as a result of the conversion: NSArray *immutable = @[ @"a", [NSNull null], @"c" ]; NSMutableArray *mutable = (__bridge id)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (__bridge CFArrayRef)immutable, kCFPropertyListMutableContainers); I tried to find any mention of NSNull not being allowed when using this function. I have a