解释工作不正常

Question

我一直使用的字典在我的代码，他们都工作，我想希望本字典的方式：

switchState["index"+("\(cellNumber)")] = cellNumber 

这里面有个for in是cellNumber是变量之一。该cellNumber代表UISwitch用户开启。

这本词典继续改写自己，我想不通为什么。该"index"+("\(cellNumber)")应该给字典一个新的密钥存储cellNumber是否正确？

我试图将此存储到NSUserDefaults作为NSDictionary和swift使我有一个String的密钥或它不会存储它。所以当我存储Dictionary时只存在一个值。你能看到上述Code有问题，或者有另一种方法来做到这一点。

感谢您的帮助。

Answer 1

// Dictionaty<key,Value> 
// subscript(key: Key) -> Value? 
// key can be Int, Double, String .... any Type: Hashable 
// value can be Any (any number, string, struct, enumeration .... class) 

var dict: Dictionary<Int,Int> = [1:1] 

// key value 
dict[10] = 100 
dict[1] = 64364 
dict[76575] = 1 

dict.forEach { (key, value) ->() in 
    print("storage for key: \(key) has value: \(value)") 
    /* 
    storage for key: 76575 has value: 1 
    storage for key: 1 has value: 64364 
    storage for key: 10 has value: 100 
    */ 
} 

var dict2 = [1:"alfa",2:"beta",3:"game"] // [2: "beta", 3: "game", 1: "alfa"] 

dict2.forEach { (key, value) ->() in 
    print("storage for key: \(key) has value: \(value)") 
    /* 
    storage for key: 2 has value: beta 
    storage for key: 3 has value: game 
    storage for key: 1 has value: alfa 
    */ 
} 
let key = 2 
dict2.updateValue("HELLO", forKey: key) // returns string "beta" (old stored value) 
print("now the value for key \(key) has value:", dict2[key]) 
/* 
now the value for key 2 has value: Optional("HELLO") 

why Optional? 
*/ 
print("the value for key \(-3) has value:", dict2[-3]) 
/* 
the value for key -3 has value: nil 

How to remove value? 
*/ 
dict2.removeValueForKey(1) // returns string "alfa" (old value) 
dict2[1]     // return nil, as expected 

必须为关键cellNumber保存开关为布尔值的字符串

var dict: [String:Bool] = [:] 
for i in 10...15 { 
    let j = i % 3 
    dict.updateValue(j == 0, forKey: "switch\(i)") 
} 
print(dict) 
/* 
["switch12": true, "switch13": false, "switch11": false, "switch14": false, "switch10": false, "switch15": true] 
*/ 

Answer 2

首先，代码可以简化为：

swiftchState["index\(cellNumber)"] = cellNumber 

您应该检查每一个循环中，cellNumber值的变化。