在indexPath处替换对象 - 包含12个部分的大数组

Question

我有一个包含12个部分的数组，我需要替换索引处的值。 我的测试代码：

textarea

第一个NSLog返回：NSMutableArray *hm = [[NSMutableArray alloc] initWithObjects:@{@"first": @[@"test1", @"test2"]}, @{@"second": @[@"test1"]}, nil]; NSLog(@"%@", [hm valueForKey:@"first"][0][0] ); [[hm valueForKey:@"first"][0] replaceObjectAtIndex:0 withObject:@"lol"]; NSLog(@"%@", hm); - 确定

替换test1

时

我需要将test1更改为某些内容。

请问我做错了吗？

Answer 1

NSMutableArray *arr = [[NSMutableArray alloc] initwithArray[[hm objectAtIndex:0]objectForKey:@"first"]];
[arr replaceObjectAtIndex:0 withObject:@"lol"];
[hm replaceObjectAtIndex:0 withObject:arr];

Answer 2

NSMutableArray *hm = [[NSMutableArray alloc] initWithObjects:@{@"first": @[@"test1", @"test2"]}, @{@"second": @[@"test1"]}, nil];

    NSLog(@"%@", [hm valueForKey:@"first"][0][0] );

    //Your inner array is immutable, change it to mutable and replace the object, That's it.
    NSMutableArray *array = [[hm valueForKey:@"first"][0] mutableCopy];
    [array replaceObjectAtIndex:0 withObject:@"lol"];
    [hm replaceObjectAtIndex:0 withObject:array];

    NSLog(@"%@", hm);  

Answer 3

你必须制作可变的字典和数组结构

NSMutableArray* names = [NSMutableArray arrayWithObjects:
                         [NSMutableDictionary dictionaryWithObjectsAndKeys:
                          @"Joe",@"firstname",
                          @"Bloggs",@"surname",
                          nil],
                         [NSMutableDictionary dictionaryWithObjectsAndKeys:
                          @"Simon",@"firstname",
                          @"Templar",@"surname",
                          nil],
                         [NSMutableDictionary dictionaryWithObjectsAndKeys:
                          @"Amelia",@"firstname",
                          @"Pond",@"surname",
                          nil],
                         nil];

NSLog(@"Before - %@",names);


[names replaceObjectAtIndex:0 withObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:
                                          @"Joe_New",@"firstname",
                                          @"Bloggs_New",@"surname",
                                          nil]];

NSLog(@"After - %@",names);

之前 - （         的 {         firstname = Joe;         surname = Bloggs;     } 下，         {         firstname =西蒙;         姓氏=圣堂武士;     }，         {         firstname = Amelia;         姓=池塘;     } ）

之后 - （         的 {         firstname =“Joe_New”;         surname =“Bloggs_New”;     } 下，         {         firstname =西蒙;         姓氏=圣堂武士;     }，         {         firstname = Amelia;         姓=池塘;     } ）

Answer 4

NSMutableArray *hm = [[NSMutableArray alloc] initWithObjects:@{@"first": @[@"test1", @"test2"]}, @{@"second": @[@"test1"]}, nil];

    NSMutableDictionary *dic=[[NSMutableDictionary alloc] initWithDictionary:[hm objectAtIndex:0]];
    NSMutableArray *array=[NSMutableArray arrayWithArray:[dic objectForKey:@"first"]];
    [array replaceObjectAtIndex:0 withObject:@"lol"];

    [dic setObject:array forKey:@"first"];

    [hm replaceObjectAtIndex:0 withObject:array];





 O/P  (ViewController.m:48) (
            (
            lol,
            test2
        ),
            {
            second =         (
                test1
            );
        }
    )