從字典數組中刪除值

Question

如何從字典數組中刪除字典？

我有一個這樣的字典數組：var posts = [[String:String]]() - 我想用特定的鍵刪除字典，我將如何繼續？我知道我可以通過執行Array.removeAtIndex(_:)或字典鍵從key.removeValue()中刪除標準數組中的值，但字典數組更加棘手。

在此先感謝！

Answer 1

如果我理解你的問題正確的，這應該工作

var posts: [[String:String]] = [ 
    ["a": "1", "b": "2"], 
    ["x": "3", "y": "4"], 
    ["a": "5", "y": "6"] 
] 

for (index, var post) in posts.enumerate() { 
    post.removeValueForKey("a") 
    posts[index] = post 
} 

/* 
This will posts = [ 
    ["b": "2"], 
    ["y": "4", "x": "3"], 
    ["y": "6"] 
] 
*/ 

由於兩個你的字典和包裹數組是值類型，只是修改循環內的post將修改字典的副本（我們創造了它通過聲明它使用var），所以得出結論，我們需要將值設置爲index到字典的新修改版本

Answer 2

刪除與給定的關鍵

let input = [ 
    [ 
     "Key 1" : "Value 1", 
     "Key 2" : "Value 2", 
    ], 
    [ 
     "Key 1" : "Value 1", 
     "Key 2" : "Value 2", 
    ], 
    [ 
     "Key 1" : "Value 1", 
     "Key 2" : "Value 2", 
     "Key 3" : "Value 3", 
    ], 
] 

let keyToRemove = "Key 3" 

//keep dicts only if their value for keyToRemove is nil (meaning key doesn't exist) 
let result = input.filter{ $0[keyToRemove] == nil } 

print("Input:\n") 
dump(input) 
print("\n\nAfter removing all dicts which have the key \"\(keyToRemove)\":\n") 
dump(result) 

所有詞典可以在行動here看到這個代碼。

卸下只能用給定的密鑰

var result = input 
//keep dicts only if their value for keyToRemove is nil (meaning key doesn't exist) 
for (index, dict) in result.enumerate() { 
    if (dict[keyToRemove] != nil) { result.removeAtIndex(index) } 
} 

print("Input:\n") 
dump(input) 
print("\n\nAfter removing all dicts which have the key \"\(keyToRemove)\":\n") 
dump(result) 

第一詞典可以在行動here看到這個代碼。