如何插入詞典

Question

我要插入與現有的字典中的相應價值的關鍵值爲新的密鑰......

我能夠在字典中現有的密鑰設定值，但我無法添加新的鍵值...

任何幫助，將不勝感激。

Answer 1

使用的NSMutableDictionary

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

更新斯威夫特：

以下是上述

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

提到的代碼的確切迅速複製，但我會建議你用斯威夫特字典的路要走。

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" 

Answer 2

NSDictionnary是不可變的。改爲使用NSMuteableDictiory。

adding對象：setObject:forKey:

編輯
測試，如果關鍵是存在：

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

Answer 3

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

通過使用這種方法，我們可以將新值添加到的NSMutableDictionary

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

要知道wheather關鍵在字典中

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

Answer 4

你好我收到內容來自json的字典格式，並從那我加入到其他字典的內容

//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]; 

    }];