Question

我有以下数组，但是，有一种方法可以在以下初始化后为key中的每个字典项添加新的value和NSMutableArray（例如年龄）。

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

Answer 1

您可以使用dip链接执行此操作。

以下是示例代码：

NSMutableDictionary mutableCopy = (NSMutableDictionary )CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFDictionaryRef)originalDictionary, kCFPropertyListMutableContainers);

https://developer.apple.com/reference/corefoundation/1429997-cfpropertylistcreatedeepcopy?language=objc

Answer 2

如果您可以将字典数组定义为可变字典，那么您可以按照以下方式执行所需的操作：

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];
for (NSMutableDictionary *dic in names) {
    dic[@"age"] = @21;
}

请注意，初始数组中的每个元素现在都是NSMutableDictionary intsances而不是NSDictioanry。如果由于某种原因你不能这样做，那么你需要从数组中获取每个字典，将其转换为可变实例，然后用新的字典实例替换相关的数组元素。

如果您无法为数组创建NSMutableDictionary个实例，那么您需要的代码将如下所示：

NSMutableArray* names = [NSMutableArray arrayWithObjects:
                         [NSDictionary dictionaryWithObjectsAndKeys:
                          @"Joe",@"firstname",
                          @"Bloggs",@"surname",
                          nil],
                         [NSDictionary dictionaryWithObjectsAndKeys:
                          @"Simon",@"firstname",
                          @"Templar",@"surname",
                          nil],
                         [NSDictionary dictionaryWithObjectsAndKeys:
                          @"Amelia",@"firstname",
                          @"Pond",@"surname",
                          nil],
                         nil];
[names enumerateObjectsUsingBlock:^(NSDictionary *dic, NSUInteger idx, BOOL * _Nonnull stop) {
    NSMutableDictionary *dic2 = [dic mutableCopy];
    dic2[@"age"] = @21;
    names[idx] = dic2;
}];

Answer 3

如果要在Dictionary中添加键和值，请使用NSMutableDictionary并在字典中添加键和值。

以下是代码：

NSMutableArray* names = [NSMutableArray arrayWithObjects:
                             [NSDictionary dictionaryWithObjectsAndKeys:
                              @"Joe",@"firstname",
                              @"Bloggs",@"surname",
                              nil],
                             [NSDictionary dictionaryWithObjectsAndKeys:
                              @"Simon",@"firstname",
                              @"Templar",@"surname",
                              nil],
                             [NSDictionary dictionaryWithObjectsAndKeys:
                              @"Amelia",@"firstname",
                              @"Pond",@"surname",
                              nil],
                             nil];
    for (int i=0; i<names.count; i++) {
        NSMutableDictionary *name = [NSMutableDictionary dictionaryWithDictionary:names[i]];
        NSDictionary *test = [NSDictionary dictionaryWithObject:@"Test" forKey:@"Demo"];
        [name addEntriesFromDictionary:test];
        names[i] = name;
    }
    NSLog(@"%@",names);

在现有的NSMutableArray中添加新值和键

3 个答案: