and good job , well basically i have array like this :
let imageArray = [ ["image0"] , ["image11","image12"] , ["image2"], ["image31","image32","image33"] ]
In this point i want to put for example first item of each nested array into a new array like this :
var newArray = ["image0","image11","image2","image31"]
And also i want to have a condition for example if "image31" clicked we have a new page that show ervery images of that first array show us, like ["image31", "image32", "image33"]
So could you tell any idea how can implement like this?
You can try
let res = imageArray.map { $0.first! }
When clicked use the index to access other elements , say from above index 3 image is clicked then use
let resImages = imageArray[clickedIndex]
Edit:
let arr = ["images/product/2021-05-02T09-47-17.699Z-download (2).jpg"]
let res = arr.map { $0[$0.range(of: "images/product/")!.upperBound...] }
print(res)
Using simple data structures (like arrays) to model complex data is rarely the best approach.
In this case I would create a struct ImageList and then create an array of this struct
struct ImageList {
let images: [String]
var firstImage: String? {
return self.images.first
}
}
You can use map to create the array from your current source, if required
imageListArray = imageArray.map { ImageList(images:$0) }
Now you can have an index that is associated with an ImageList struct - imageListArray[i].firstImage! is the value you want for your list and iageListArray[i].images is the array you want for your second requirement.
Related
I am currently having a big issue sorting my Data alphabetically in a 2D array. I'm going to try to give you every detail to be as clear as possible.
Currently, I am fetching my contacts with the CNContactStore. This all works fine. I am able to retrieve all the data I want out of my contacts.
Now, I created the following struct:
struct FavoritableContact {
let contact: CNContact
var hasFavorited: Bool
}
With this, I declared and initialized the following array:
var favoritableContacts = [FavoritableContact]()
Once I retrieved my contacts, I simply appended them to favoritableContacts;
try store.enumerateContacts(with: request, usingBlock: { (contact, stopPointerIfYouWantToStopEnumerating) in
favoritableContacts.append(FavoritableContact(contact: contact, hasFavorited: false))
})
To sort them in alphabetical order in the same array, I simply did the following:
var sortedContacts = favoritableContacts.sorted { $0.contact.familyName < $1.contact.familyName }
Now if possible, I want to create the following 2D array,
var 2D = [
[FavoritableContact] //"A"
[FavoritableContact], //"B"
[FavoritableContact], //"C"
[FavoritableContact], //"D"
...
]
I am just not sure how to take my sortedContacts array and separate alphabetically.
I am very new here, If I forgot something, or I didn't do somethign right please let me know.
As was pointed out in the comments, a dictionary with first letters as keys is probably the better way to go as it is much easier to access, though perhaps you have a reason for wanting to use a 2d array instead. To achieve that you could do something like this:
//Create an empty array filled with 26 arrays of FavorableContact
var array2d = Array<[FavoritableContact]>(repeating: [FavoritableContact](), count: 26)
//Find the ascii value for "A" to use as your base
let aAscii = Int("A".unicodeScalars.filter({ $0.isASCII }).map({ $0.value })[0]) //This returns 65, btw, so you could also just hardcode
//Go through your original array, find the first letter of each contact, and append to the correct array
favoritableContacts.forEach { (contact) in
//Get the ascii value for the first letter
let firstLetter = Int(contact.contact.familyName.prefix(1).uppercased().unicodeScalars.filter({ $0.isASCII }).map({ $0.value })[0])
//Append to the array for this letter by subtracting the ascii value for "A" from the ascii value for the uppercased version of this letter.
array2d[firstLetter - aAscii].append(contact)
}
This is not the cleanest thing in the world, and it assumes standard English language alphabet with no diacritics, symbols, numbers or anything else. Assuming that is true it gets the job done.
Could use something like this.
var contactsLeftToSort : [FavoritableContact] = []
var doubleArray : [[FavoritableContact]?] = [[FavoritableContact]?]()
var index : Int = 0
for char in "ABCDEFGHIJKLMNOPQRSTUV" {
doubleArray.append(nil)
var i = 0
while i < contactsLeftToSort.count {
let contact = contactsLeftToSort[i]
if contact.name.first == char {
doubleArray[index] == nil ? doubleArray[index] = [contact] : doubleArray[index]!.append(contact)
contactsLeftToSort.remove(at: i)
}
//assuming original list is alphabetized.. if not, delete this line.
if contact.name.first! > char { break }
i += 1
}
index += 1
}
As I wrote in the comments above, I think you can achieve this in a much more elegant way by using a dictionary instead of an array.
SWIFT 4
let sortedContacts: [FavoritableContact] = ... // An array of FavoritableContact objects, they should be sorted
let groupedContacts = Dictionary(grouping: contacts, by { $0.familyName.first! })
You now have a dictionary of all your contacts where the keys are the alphabetical letters (ie. A-Z) and the values are arrays of sorted FavoritableContact objects (assuming you sorted the big array of FavoritableContacts before creating the dictionary).
If you wanted to use this as the datasource for your tableview, you would make the number of sections all the possible first letters of family names. For the number of rows in each section, you return the count of the array for the key like so:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
let letterForSection = letterForSection() // Custom method to get the section of the letter
return contactsDict[letterForSection].count
}
The rest of the datasource methods would work in a similar way.
Man, all of these answers are really over-complicating this. All you need is something along the lines of:
let groupedContacts = Dictionary(grouping: contacts, by: { $0.contact.firstName.first! })
for initial, contacts in groupedContacts.lazy.sorted().{ $0.key < $1.key} {
print("#################", initial)
contacts.forEach{ print($0) }
}
I wonder if its possible to store both Data and String in a array?
I need a way to store images that user picks together with the image names inside a array so I later can append it to my API request when I upload it.
Now I am using a array tuple that I later append Data and String to
var imgArray = [(Data, String)]()
Then I add data to that array tuple like this:
if let firstImage = self.firstImage {
if let firstImageData = firstImage.compressImage() {
self.imgArray.append(firstImageData, self.randomImageName(length: 15))
}
I use the code above for everyimage the user uploads and it works, imgArray gets populated with both Data and String which I later send to my API.
But is there a way to use a array to store Data and String values to?
I am not sure if tuples is the best solution
}
Apple discourages from using tuples as data source.
Tuples are useful for temporary groups of related values. They are not suited to the creation of complex data structures. If your data structure is likely to persist beyond a temporary scope, model it as a class or structure, rather than as a tuple
The (object oriented) Swift way is a struct:
struct ImageData {
var data : Data
var name : String
}
var imgArray = [ImageData]()
if let firstImage = self.firstImage {
if let firstImageData = firstImage.compressImage() {
self.imgArray.append(ImageData(data:firstImageData, name:self.randomImageName(length: 15))
}
The benefit is to get the members by name
let imageName = imgArray[0].name
In my app I have two struct arrays and I want to remove common items from one of them. My struct:
struct PeopleSelectItem {
var name = ""
var id = ""
var added = false
}
My arrays:
var people : [PeopleSelectItem] = []
var selectedPeople : [PeopleSelectItem] = []
I want to remove items from people array if they exist (compare by id) on selectedPeople array.
I tried several array filtering and converting to set but none of them worked. What can I do here?
Thanks!
Get an array of all ids in selectedPeople
let selectedPeopleIDs = selectedPeople.map(\.id)
Filter the items whose id is not in the array
let filteredPeople = people.filter { !selectedPeopleIDs.contains($0.id) }
If you know that people equal each other if the id is the same then you can conform your struct to the Equatable protocol and you can use the array filter method.
struct PeopleSelectItem : Equatable {
var name = ""
var id = ""
var added = false
}
func ==(lhs: PeopleSelectItem, rhs: PeopleSelectItem) -> Bool {
return lhs.id == rhs.id
}
func filterPeople() {
//swift 2, 3:
people = people.filter{!selectedPeople.contains($0)}
//swift older versions:
people = people.filter{!contains(selectedPeople, $0)}
}
If people might have a significant amount of entries, performance should be considered. So, instead of searching with an n^2 algorithm, you should make use of Swifts dictionary and the corresponding hash-search to find items.
If Id is unique for people then I would store them in a dictionary like:
var peopleDict: [String:PeopleSelectItem] = [:]()
You can easily convert from the array you have to this dictionary:
people.foreach {peopleDict[$0.id] = $0}
With this dictionary it's very easy to delete single entries:
selectedPeople.foreach {peopleDict.remove($0.id)}
Optionally to switch back to an array for people you just say:
let filteredPeople = peopleDict.values as [PeopleSelectItem]
Remarks
I assumed, that selectedPeople is smaller then the base of all people. If this is not the case, you should pu selectedPeople in a dictionary.
did I say I like this Spark like api? I think I do so.
I just wrote that code from top of my mind. If it is not completely syntactically correct let me know and I correct it.
I have two separate arrays that I want to import into a dictionary. Order is extremely important because both arrays must match in index
struct MyVariables {
static var users:NSArray!
static var img:NSArray!
}
var data = SearchVC.getData()
MyVariables.users = data.users; //array 1 (key)
MyVariables.img = data.img; //array 2
// Goal is to insert these arrays into a dictionary while maintaing the matching indexes on both arrays
// Dictonary (MyVariables.img, key: MyVariables.users)
A Dictionary does not have a particular order. However, if both arrays have the same length, it is quite easy to iterate over them together:
var dictionary = [NSString: AnyObject]()
for var index = 0; index < data.users.count; index++ {
let img = data.img as! NSString
dictionary[img] = data.users[index]
}
Or, as #robertvojta suggested, use the zip() method:
var dictionary = [NSString: AnyObject]()
for (user, image) in zip(data.users, data.img) {
let img = image as! NSString
dictionary[img] = user
}
The key in a dictionary in swift must be hashable. i.e., not AnyObject.
Assuming you can replace some of your untyped Swift arrays, or cast them like so:
struct MyVariables {
var users:Array<AnyObject>
var img:Array<String>
}
then you can iterate through 1 array using a preferred Swift method and access the second using indexing:
var dictionary = Dictionary<String, AnyObject>()
for (index, element) in enumerate(MyVariables.img) {
dictionary[element] = MyVariables.users[index]
}
Use for loop for travels the array in that as per index access keys and values respective array and add it in dictionary. Its so simple so you can achive your goal using it.
I hope it will help you!
I have a dictionary set up as:
var jDict = Dictionary<String, AnyObject[]>()
Where the arrays are either a collection of custom buttons (JunkButton) or Labels (JunkLabels).
I am having an issue when trying to access the members of the arrays contained in the Dictionary as follows:
let thisArray = jDict[key]
var aButton = thisArray[0] //Gives error: 'AnyObject[]? does not have a member named 'subscript'
I can get around this by downcasting the whole array as follows:
if let aArray = thisArray as? JunkButton[]{
var aButton = aArray[0]
}
This seems very cumbersome especially if I am sure I know what type the array is made up of beforehand. Is there a way to cast thisArray when it is created that would allow me to extract its elements without unwrapping them each time?
Dictionary always give you Optional value.
Your code is like this
let thisArray : Optional<AnyObject[]> = jDict[key]
You need to unwrap it to get non-optional value
let thisArray = jDict[key]! // thisArray is AnyObject[]
You really shouldn't use a dictionary for this. Swift makes it very easy to use custom little structs or classes instead of dictionaries:
struct JunkItems {
var buttons: [JunkButton] = []
var labels: [JunkLabel] = []
}
Then you can access those items like this without downcasting:
for button in junkItems.buttons {
// ...
}
Or:
if let button = junkItems.buttons[0] {
// ...
}
Btw, the array notation [JunkButton] is new in beta 3.