I've got a JSON as below.
odds: {
0501: {
x: 2.75,
description: "a"
},
0502: {
x: 3.25,
description: "b"
},
0513: {
x: 3.5,
description: "c"
},
0503: {
x: 3.5,
description: "d"
},
0505: {
x: 7.5,
description: "e"
},
0504: {
x: 7.5,
description: "f"
},
0512: {
x: 10,
description: "g"
}
}
This hash comes from HTTP response as I want to show but the thing that I use JSONModel to map it and there is only way to map that NSDictionary. When map this JSON to NSDictionary (as you can guess) this an unordered and sequence of data comes up mixed.
So, how to map this JSON, without broke up its sequence using JSONModel and NSDictionary ?
NSDictionary is inherently unordered:
Are keys and values in an NSDictionary ordered?
If you want to preserve the order of key-value entries, you need to use a data structure other than NSDictionary. Any library that passes your data through an NSDictionary cannot preserve the order.
Something I've done in this situation is to sort the dictionary keys in a separate array, in addition to the dictionary. Use the ordered key array to determine how to display your dictionary values.
Dictionaries can not be sorted, but as your JSON seems to be an array of objects, iterate thru your resulting NSDictionary with for...in and add the elements to a mutable array.
Afterwards sort the resulting array using .sortInPlace by comparing the x-value.
Related
I have a random dictionary, I want to iterate over all objects that are inside that dictionary. Is there a way to find keyPath of object that is inside the dictionary?
Let's say we have this dictionary .
{
"glossary": {
"title": "example glossary",
"GlossDiv": {
"title": "S",
"GlossList": {
"GlossEntry": {
"ID": "SGML",
"SortAs": "SGML",
"GlossTerm": "Standard Generalized Markup Language",
"Acronym": "SGML",
"Abbrev": "ISO 8879:1986",
"GlossDef": {
"para": "A meta-markup language, used to create markup languages such as DocBook.",
"GlossSeeAlso": [
"GML",
"XML"
]
},
"GlossSee": "markup"
}
}
}
}
}
Now I want to find keyPath of GlossEntry or any other object.
Consider:
You can obtain all the keys in a dictionary and iterate over them. E.g. for (NSString *key in dictionary) {...}
Given a key you can obtain the matching value and test whether it is itself a dictionary.
Recursion is your friend. You could write a function which takes a current key path prefix, a dictionary, and a mutable array to add found key paths to. The implementation of this would involve (1), (2) and a recursive call.
Now write yourself some code. If you get stuck ask a new question, include your code, and explain where you are stuck.
HTH
I have an array of dictionaries [[String : AnyObject]] called rooms in a User object - each dictionary holds a name as the String and an id as the AnyObject.
I want to populate a table view with the names, so I'm trying to loop through the array and grab the String values from the dicts.
if let roomDict = myUser.rooms as? [[String : AnyObject]] {
for (roomNames, _) in roomDict {
cell.textLabel?.text = roomNames
}
}
I'm relatively new and from what I've seen in tutorials and such when looping through dictionaries, you use the underscore to specify that you don't want the second value. So just grab all the first values (in this case, the names), and set them to the roomNames variable.
However I'm confused here because I'm not looping through a dictionary, I'm looping through an array of dictionaries. So I'm not sure how to do that. I did a search and the results I saw generally were asking about JSON, which isn't the case here. How can I do this?
Thanks for any help!
Firstly, your dictionary structure isn't ideal. Rather than having the key as the room name and the value as the identifier, your dictionary should have known key names, with variable values. Keys should not be "data" in a dictionary.
So, rather than
["room1":1]
it would be better if it were
["roomName":"room1", "roomID":1]
with your current structure, however, assuming that there is only one key per dictionary and that is the room name, you can get the names with:
if let rooms = myUser.rooms as? [[String : AnyObject]] {
roomNames = rooms.map({ $0.keys.first!})
}
If you use the better structure I suggested then it would be
if let rooms = myUser.rooms as? [[String : AnyObject]] {
roomNames = rooms.map({ $0["roomName"] as? String ?? ""})
}
I'm not clear about your data structure. If you have an array of dictionaries, and you want all the keys, you could use code like this:
let array = [
["key1": "value1",
"key2": "value2",
"key3": "value3",
"key4": "value4"],
["key5": "value5",
"key6": "value6",
"key7": "value7",
"key8": "value8"],
["key9": "value9",
"key10": "value10",
"key11": "value11",
"key12": "value12"]
]
let keys = array
.map{$0.keys}
.reduce([], +)
print(keys)
That will give you an array of all the keys from all the dictionaries. The keys from each dictionary will be in a jumbled order however, since dictionaries are unordered. You'll get the keys from each inner dictionary in a jumbled order, followed by the keys from the next dictionary in the array, etc.
Sample output:
["key2", "key3", "key4", "key1", "key7", "key8", "key5", "key6", "key9", "key10", "key12", "key11"]
If you want to sort the keys, you can do that:
let keys = array
.map{$0.keys}
.reduce([], +)
.sorted{$0.compare($1, options: .numeric) == .orderedAscending}
(In the above code I'm using the String class's compare(_:options:) function with an options value of .numeric so that "key11" sorts after "key10" instead of ["key1", "key11", "key12", "key2"], which you get from standard string ordering.)
The output of the sorted version (with the .numeric option) is:
["key1", "key2", "key3", "key4", "key5", "key6", "key7", "key8", "key9", "key10", "key11", "key12"]
Without the .numeric option, the output would be:
["key1", "key10", "key11", "key12", "key2", "key3", "key4", "key5", "key6", "key7", "key8", "key9"]
If your keys contain mixed upper/lower case and you want to ignore it, you'd use options of [.numeric, .caseInsensitive] (case insensitive sorting where numbers within strings are compared using numeric value.)
Is there any built-in way to create an ordered map in Swift 2? Arrays [T] are sorted by the order that objects are appended to it, but dictionaries [K : V] aren't ordered.
For example
var myArray: [String] = []
myArray.append("val1")
myArray.append("val2")
myArray.append("val3")
//will always print "val1, val2, val3"
print(myArray)
var myDictionary: [String : String] = [:]
myDictionary["key1"] = "val1"
myDictionary["key2"] = "val2"
myDictionary["key3"] = "val3"
//Will print "[key1: val1, key3: val3, key2: val2]"
//instead of "[key1: val1, key2: val2, key3: val3]"
print(myDictionary)
Are there any built-in ways to create an ordered key : value map that is ordered in the same way that an array is, or will I have to create my own class?
I would like to avoid creating my own class if at all possible, because whatever is included by Swift would most likely be more efficient.
You can order them by having keys with type Int.
var myDictionary: [Int: [String: String]]?
or
var myDictionary: [Int: (String, String)]?
I recommend the first one since it is a more common format (JSON for example).
Just use an array of tuples instead. Sort by whatever you like. All "built-in".
var array = [(name: String, value: String)]()
// add elements
array.sort() { $0.name < $1.name }
// or
array.sort() { $0.0 < $1.0 }
"If you need an ordered collection of key-value pairs and don’t need the fast key lookup that Dictionary provides, see the DictionaryLiteral type for an alternative." - https://developer.apple.com/reference/swift/dictionary
You can use KeyValuePairs,
from documentation:
Use a KeyValuePairs instance when you need an ordered collection of key-value pairs and don’t require the fast key lookup that the Dictionary type provides.
let pairs: KeyValuePairs = ["john": 1,"ben": 2,"bob": 3,"hans": 4]
print(pairs.first!)
//prints (key: "john", value: 1)
if your keys confirm to Comparable, you can create a sorted dictionary from your unsorted dictionary as follows
let sortedDictionary = unsortedDictionary.sorted() { $0.key > $1.key }
As Matt says, dictionaries (and sets) are unordered collections in Swift (and in Objective-C). This is by design.
If you want you can create an array of your dictionary's keys and sort that into any order you want, and then use it to fetch items from your dictionary.
NSDictionary has a method allKeys that gives you all the keys of your dictionary in an array. I seem to remember something similar for Swift Dictionary objects, but I'm not sure. I'm still learning the nuances of Swift.
EDIT:
For Swift Dictionaries it's someDictionary.keys
You can use the official OrderedDictionary from the original Swift Repo
The ordered collections currently contain:
Ordered Dictionary (That you are looking for)
Ordered Set
They said it is going to be merged in the Swift itself soon (in WWDC21)
Swift does not include any built-in ordered dictionary capability, and as far as I know, Swift 2 doesn't either
Then you shall create your own. You can check out these tutorials for help:
http://timekl.com/blog/2014/06/02/learning-swift-ordered-dictionaries/
http://www.raywenderlich.com/82572/swift-generics-tutorial
I know i am l8 to the party but did you look into NSMutableOrderedSet ?
https://developer.apple.com/reference/foundation/nsorderedset
You can use ordered sets as an alternative to arrays when the order of
elements is important and performance in testing whether an object is
contained in the set is a consideration—testing for membership of an
array is slower than testing for membership of a set.
var orderedDictionary = [(key:String, value:String)]()
As others have said, there's no built in support for this type of structure. It's possible they will add an implementation to the standard library at some point, but given it's relatively rare for it to be the best solution in most applications, so I wouldn't hold your breath.
One alternative is the OrderedDictionary project. Since it adheres to BidirectionalCollection you get most of the same APIs you're probably used to using with other Collection Types, and it appears to be (currently) reasonably well maintained.
Here's what I did, pretty straightforward:
let array = [
["foo": "bar"],
["foo": "bar"],
["foo": "bar"],
["foo": "bar"],
["foo": "bar"],
["foo": "bar"]
]
// usage
for item in array {
let key = item.keys.first!
let value = item.values.first!
print(key, value)
}
Keys aren't unique as this isn't a Dictionary but an Array but you can use the array keys.
use Dictionary.enumerated()
example:
let dict = [
"foo": 1,
"bar": 2,
"baz": 3,
"hoge": 4,
"qux": 5
]
for (offset: offset, element: (key: key, value: value)) in dict.enumerated() {
print("\(offset): '\(key)':\(value)")
}
// Prints "0: 'bar':2"
// Prints "1: 'hoge':4"
// Prints "2: 'qux':5"
// Prints "3: 'baz':3"
// Prints "4: 'foo':1"
I have a dictionary like <String,Loto> and Loto is object like below;
Loto:
{
"success": true,
"data": {
"oid": "64kbbqi8dbxygb00",
"hafta": 961,
"buyukIkramiyeKazananIl": "",
"cekilisTarihi": "11/04/2015",
"cekilisTuru": "SAYISAL_LOTO",
"rakamlar": "03#02#48#16#15#08",
"rakamlarNumaraSirasi": "02 - 03 - 08 - 15 - 16 - 48",
"devretti": false,
"devirSayisi": 0,
"bilenKisiler": [
{
"oid": "64kbbxi8dbxyg403",
"kisiBasinaDusenIkramiye": 7.35,
"kisiSayisi": 185712,
"tur": "$3_BILEN"
},
{
"oid": "64kbbxi8dbxyg402",
"kisiBasinaDusenIkramiye": 53.05,
"kisiSayisi": 9146,
"tur": "$4_BILEN"
},
{
"oid": "64kbbxi8dbxyg401",
"kisiBasinaDusenIkramiye": 4532.2,
"kisiSayisi": 142,
"tur": "$5_BILEN"
},
{
"oid": "64kbbxi8dbxyg400",
"kisiBasinaDusenIkramiye": 1528438.75,
"kisiSayisi": 1,
"tur": "$6_BILEN"
}
],
"buyukIkrKazananIlIlceler": [
{
"il": "10",
"ilView": "BALIKESÄ°R",
"ilce": "01001",
"ilceView": "AYVALIK"
}
],
"kibrisHasilati": 51127,
"devirTutari": 0.09,
"kolonSayisi": 10537872,
"kdv": 1599672.97,
"toplamHasilat": 10537872,
"hasilat": 8938199.03,
"sov": 893819.9,
"ikramiyeEH": 8044379.129999999,
"buyukIkramiye": 1528432.03,
"haftayaDevredenTutar": 0
}
}
So my dictionary like <"11042015",Loto> and i want to sort this dictionary by "hafta" property of loto object.
How can i do this? Please help me!
If Loto is an object with a hafta property, you can sort your dictionary by passing it into the sorted function, along with a closure that tells it how to order the entries:
sorted(dict) { $0.1.hafta < $1.1.hafta }
($0.1 and $1.1 because dictionaries present as a sequence of key/value pairs - you want to sort by a property of the value i.e. tuple entry 1)
Note, this will give you back a sorted array, of type [(String,Loto)] pairs, rather than a dictionary (as Swift dictionaries are unordered).
(if Loto is not really an object but rather another dictionary, you might need to do {$0.1["hafta"] < $1.1["hafta"]} - it really depends on how you’re holding your data - the good news is you don’t need to worry about optionals, since they can be compared with <)
If you don’t need the keys, just sort the values:
sorted(dict.values) { $0.hafta < $1.hafta }
which will give you back a sorted array of type [Loto]
Dictionaries are not ordered. What you need is to convert it to array, and then sort it. So something like this.
let lotoArray = lotoDictionary.allObjects as [Loto]
lotoArray.sort { $0.hafta < $1.hafta }
You can't. The keys of a dictionary are not sorted. You can get an array of the values and sort that array.
I need to load an array of tuple from json file. I tried the following but it doesn't work.
my json file is:
{ "broken" : [(1,1), (1,2), (2,2), (3,1)]}
Then I'm using loadsjsonfrombundle to load data from JSON as follow:
let broken = [(Int, Int)]!
if let dictionary = Dictionary<String, AnyObject>.loadsjsonfrombundle(filename) {
broken = (dictionary["broken"]) as Array
}
Any suggestion?
Thanks.
An array is an ordered collection of values. An array begins with [
(left bracket) and ends with ] (right bracket). Values are separated
by , (comma).
A value can be a string in double quotes, or a number, or true or
false or null, or an object or an array. These structures can be
nested.
So this is invalid JSON format
{ "broken" : [(1,1), (1,2), (2,2), (3,1)]}
because (1,1) is not a string in double quotes, or a number, or true or
false or null, or an object or an array
The possible correct format would be
{ "broken" : [[1,1], [1,2], [2,2], [3,1]]}
in this case you can iterate trough array of arrays and initialize your tuples with array.firstObject and array.lastObject
About JSON