How do I get the key at a specific index from a Dictionary in Swift

Question

I have a Dictionary in Swift and I would like to get a key at a specific index    var myDict   Dictionary lt String MyClass gt    Dictionary lt String MyClass gt      I know that I can iterate over the keys and log them   for key in myDict keys       NSLog  key     key         However  strangely enough  something like this is not possible  var key   String   myDict keys 0    Why

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Here is an example  using Swift 1 2  var person     name   Sean    gender   male   person keys array 1      gender   get a dictionary key at specific index  person values array 1      male   get a dictionary value at specific index

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I was looking for something like a LinkedHashMap in Java  Neither Swift nor Objective-C  have one if I m not mistaken   My initial thought was to wrap my dictionary in an Array    String  UIImage   but then I realized that grabbing the key from the dictionary was wacky with Array dict  index  key so I went with Tuples  Now my array looks like   String  UIImage   so I can retrieve it by tuple 0  No more converting it to an Array  Just my 2 cents

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Swift 3   Array   can be useful to do this    Get Key     let index   5    Int Value Array myDict  index  key   Get Value     Array myDict  index  value

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From https   developer apple com library prerelease ios documentation swift conceptual swift programming language CollectionTypes html   If you need to use a dictionary   s keys or values with an API that takes an Array instance  initialize a new array with the keys or values property   let airportCodes    String  airports keys     airportCodes is   TYO    LHR      let airportNames    String  airports values     airportNames is   Tokyo    London Heathrow

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SWIFT 3  Example for the first element  let wordByLanguage     English   5   Spanish   4   Polish   3   Arabic   2   if let firstLang   wordByLanguage first  key       print firstLang      English

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Here is a small extension for accessing keys and values in dictionary by index   extension Dictionary       subscript i  Int  - gt   key  Key  value  Value            return self index startIndex  offsetBy  i

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You can iterate over a dictionary and grab an index with for-in and enumerate  like others have said  there is no guarantee it will come out ordered like below   let dict     c   123   d   045   a   456   for  index  entry  in enumerate dict        println index       0       1        2     println entry        d  45   c  123   a  456      If you want to sort first    var sortedKeysArray   sorted dict     0 0  lt   1 0   println sortedKeysArray         a  456    c  123    d  45    var sortedValuesArray   sorted dict     0 1  lt   1 1   println sortedValuesArray       d  45    c  123    a  456     then iterate   for  index  entry  in enumerate sortedKeysArray        println index        0   1   2     println entry 0      a   c   d     println entry 1      456 123 45     If you want to create an ordered dictionary  you should look into Generics

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In Swift 3 try to use this code to get Key-Value Pair  tuple  at given index    extension Dictionary       subscript i Int  - gt   key Key value Value            get               return self index startIndex  offsetBy  i

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SWIFT 4    Slightly off-topic  But here is if you have an Array of Dictionaries i e     String   String     var array has dictionary        Start of array        Dictionary 1              name     xxxx         age     xxxx         last name   xxx               Dictionary 2              name     yyy         age     yyy         last name   yyy               end of array   cell textLabel  text    Array array has dictionary 1   1  key    Output  age - gt  yyy

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That s because keys returns LazyMapCollection lt  Key   Value   Key gt   which can t be subscripted with an Int  One way to handle this is to advance the dictionary s startIndex by the integer that you wanted to subscript by  for example   let intIndex   1    where intIndex  lt  myDictionary count let index   myDictionary index myDictionary startIndex  offsetBy  intIndex  myDictionary keys index    Another possible solution would be to initialize an array with keys as input  then you can use integer subscripts on the result   let firstKey   Array myDictionary keys  0     or  first   Remember  dictionaries are inherently unordered  so don t expect the key at a given index to always be the same

[ios] How do I get the key at a specific index from a Dictionary in Swift?

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