Iphone 如何在字典中插入具有值的新键

我想在现有字典中插入具有相应值的键

我可以为字典中的现有键设置值，但无法添加新的键值

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任何帮助都将不胜感激。

措辞是不变的。请改用NSMuteableDictionary

对象：

setObject:forKey:

测试是否存在密钥：

[[aDict allKeys] containsObject:@"key"];

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使用NSMutableDictionary

NSMutableDictionary *yourMutableDictionary = [NSMutableDictionary alloc] init];
[yourMutableDictionary setObject:@"Value" forKey:@"your key"];

[dict setObject:@"Value" forKey:@"Key"];

Swift更新：

以下是上述代码的准确swift副本

var yourMutableDictionary = NSMutableDictionary()
yourMutableDictionary.setObject("Value", forKey: "Key")

但我建议你还是用斯威夫特字典的方式

var yourMutableDictionary = [String: AnyObject]() //Open close bracket represents initialization

//The reason for AnyObject is a dictionary's value can be String or
//Array or Dictionary so it is generically written as AnyObject

yourMutableDictionary["Key"] = "Value"

通过使用此方法，我们可以将新值添加到NSMutableDictionary

NSMutableDictionary *yourMutableDictionary = [NSMutableDictionary alloc] init];
[yourMutableDictionary setObject:@"Value" forKey:@"your key"];

[dict setObject:@"Value" forKey:@"Key"];

要知道字典里是否有钥匙

[[dict allKeys] containsObject:@"key"];

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嗨，我以字典的格式从json中获取内容，并从中将内容添加到其他字典中

  //here contract is my json dictionary 
  NSArray *projectDBList =[contract allKeys];//listing all the keys in dict 

  NSMutableDictionary *projectsList=[[NSMutableDictionary alloc]init];

  [projectDBList enumerateObjectsUsingBlock:^(NSString * obj, NSUInteger idx, BOOL *stop) {

  [projectsList setObject:[contract objectForKey:obj] forKey:obj];

  }];

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对于nsmutable dictionary，如何插入新的键值如何知道给定的键是否存在于dictionary[yourMutableDictionary allKeys]中；这将返回该字典中所有键的数组，并将其与给定的键进行比较，顺便说一下，如果您必须转换回NSDictionary，您可以将其转换为NSDictionary，如将其转换为NSDictionary，以及如何将任何对象类添加为value和int作为key？cv:：Mat作为value和int作为key如何将其添加到NSMutableDictionary？