I have array:
let array = ["", "Therapeutic Dentistry","Surgical Dentistry","Orthopedic Dentistry","Orthodontics","Genaral Medical Questions","Children Therapeutic Dentistry","Children Surgical Dentistry"]
And i want get firs one, it's empty, how i can get this element from array?
Arrays have a first property which gives you the first element if it exists.
if let firstElement = array.first {
print(firstElement)
}
If you want the first element that is not an empty string then you can use the first(where:)
if let firstElement = arr.first(where: { $0 != "" }) {
print(firstElement)
}
Edit:
Question title was "iOS How get first element from array Swift" in the beginning which is why the answer has two parts.
let firstElement = array.first ?? DefaultValue
It means
let firstElement = array.first != nil ? array.first! : DefaultValue
DefaultValue is anything you defined.
Filter the array by removing "" values and get the first element.
array = array.filter({ $0 != "" })
if let first = array.first{
print(first)
}
Related
I am tracking a user's preferences in my iOS app using UserDefaults -- when a user selects a table cell, it adds the cell's text to my key. That part works.
Now, I want to allow the user to remove the matching key value from the key when a row is selected. If a cell says "Episode 1", it should remove the value from UserDefaults.
From the documentation, there's an instance method for removeObject. Here's what I wrote:
let defaults = UserDefaults.standard
var myarray = defaults.stringArray(forKey: "SavedStringArray") ?? [String]()
if let datastring = TableData[indexPath.row] as? String {
if !myarray.contains(datastring) {
myarray.append(datastring)
defaults.removeObject(myarray, forKey: "SavedStringArray")
defaults.synchronize()
}
This returns an error for Extra argument in call -- I assume it means myarray, but if I can't add that argument, how can I tell it to remove only one value (stored in myarray)?
If I print the UserDefaults.standard, it will return a list of stored episode values like `["First Episode", "Second Episode", "Third Episode"]
Any idea how I can remove Third Episode when that cell is clicked here?
I have following code which will work for you.
if myarray.contains(datastring) {
myarray.remove(at: myarray.index(of: datastring)!)
} else {
myarray.append(datastring)
}
defaults.set(myarray, forKey: "SavedStringArray")
This code will remove element from array and set array again in User defaults for same key, So it will replace you array with new array.
You can add if string is not present or remove the string if it is present. And then update the array.
Then set that array for the key.
if !myarray.contains(datastring) {
myarray.append(datastring)
} else {
myarray = myarray.filter{$0 != datastring}
}
defaults.set(myarray, forKey: "SavedStringArray")
You can try This logic for array of type String i.e. [String]
var arrStr:[String] = ["Cat","Rat","Mouse"]
print(arrStr)
let datastring = "Rat"
if !arrStr.contains(datastring) {
arrStr.append(datastring)
} else {
arrStr.remove(at: arrStr.index(of: datastring)!)
}
print(arrStr)
UserDefaults.standard.set(arrStr, forKey: "SavedStringArray")
UserDefaults.standard.synchronize()
I've been away for a while from swift development. And today I got bug report from my client on my old project. The thing is I used to access value from my dictionary with ease just like dictionary[key] then I already got the value, but today I got below error by doing that:
Type 'NSFastEnumerationIterator.Element' (aka 'Any') has no subscript members
and here is my code:
var rollStatusArray = NSMutableArray()
for statusDict in rollStatusArray{
if statusId == "\(statusDict["mark_status_id"]!!)"{
return "\(statusDict["mark_status_name"]!!)"
}
}
How can I access dictionary value on swift 3?
In Swift's use native type Array/[] instead of NS(Mutable)Array.
if let dicArray = rollStatusArray.objectEnumerator().allObjects as? [[String:Any]] {
for statusDict in dicArray {
//Here compiler know type of statusDict is [String:Any]
if let status_id = statusDict["mark_status_id"] as? String, status_id == statusId {
return "\(statusDict["mark_status_name"]!)"
}
}
}
Note I'm force wrapping the mark_status_name value you can use Nil coalescing operator to return empty string to remove force wrapping.
You need to tell compiler the type of your statusDict this way:
for statusDict in rollStatusArray {
if let obj = statusDict as? [String: AnyObject] {
let statusIdFromDict = obj["mark_status_id"] as? String ?? ""
if statusId == statusIdFromDict {
return statusIdFromDict
}
}
}
Using Swift 3, you can access the dictionary value the following way:
var rollStatusArray = NSMutableArray()
for statusDict in rollStatusArray{
if statusId == "\((statusDict as! NSDictionary)["mark_status_id"]!)"{
return "\((statusDict as! NSDictionary)["mark_status_name"]!)"
}
}
I have a class such as this
class FoundItem : NSObject {
var id : String!
var itemName : String!
var itemId : Int!
var foundBy : String!
var timeFound : String!
init(id: String,
itemName: String,
itemId: Int,
foundBy: String,
timeFound: String)
{
self.id = id
self.itemName = itemName
self.itemId = itemId
self.foundBy = foundBy
self.timeFound = timeFound
}
and I reference it on my
class MapViewVC: UIViewController, MKMapViewDelegate {
var found = [FoundItem]()
var filterItemName : String()
}
My FoundItem are generated by into an array of dictionaries from my class of FoundItem from a firebase query. I then get a string of that itemName that is generated from an another view controller that is a collection view on the didSelection function. I want to take that string and then filter or search the arrays with the string itemName that is equal from the itemName string from my previous viewController. Then removed the array of dictionaries that are not equal to the itemName. Not just the objects, but the entire array that contains non-equal key, value pair. I have looked for days, and I am stuck on filtering an array of dictionaries created from a class. I have looked and tried NSPredicates, for-in loops, but all that ends up happening is creating a new array or bool that finds my values or keys are equal. Here is the current function I have written.
func filterArrayBySearch() {
if self.filterItemName != nil {
dump(found)
let namePredicate = NSPredicate(format: "itemName like %#", "\(filterItemName)")
let nameFilter = found.filter { namePredicate.evaluate(with: $0) }
var crossRefNames = [String: [FoundItem]]()
for nameItemArr in found {
let listName = nameItem.itemName
let key = listName
if crossRefNames.index(forKey: key!) != nil {
crossRefNames[key!]?.append(nameItemArr)
if !("\(key)" == "\(filterItemName!)") {
print("------------- Success have found [[[[[[ \(key!) ]]]]]] and \(filterItemName!) to be equal!!")
// crossRefNames[key!]?.append(nameItemArr)
} else {
print("!! Could not find if \(key!) and \(filterItemName!) are equal !!")
}
} else {
crossRefNames[key!] = [nameItemArr]
}
}
} else {
print("No Data from Search/FilterVC Controller")
}
}
Can anyone help? It seems like it would be the simple task to find the value and then filter out the dictionaries that are not equal to the itemName string, but I keep hitting a wall. And running into for-in loops myself :P trying different things to achieve the same task.
I hope I understood what you were asking. You mention an "array of dictionaries" but you don't actually have an array of dictionaries anywhere in the code you've posted.
As far as I can tell, you are asking how to find all the entries in the found array for which itemName equals the filterItemName property.
If so, all you should need to do is:
let foundItems = found.filter { $0.itemName == filterItemName }
That's it.
Some other ideas:
If you want to search for items where filterItemName is contained in the itemName, you could do something like this:
let foundItems = found.filter { $0.itemName.contains(filterItemName) }
You could also make use of the lowercased() function if you want to do case-insensitive search.
You could also return properties of your found elements into an array:
let foundIds = found.filter { $0.itemName == filterItemName }.map { $0.itemId }
Sort array of dictionary using the following way
var dict:[[String:AnyObject]] = sortedArray.filter{($0["parentId"] as! String) == "compareId"}
The filter function loops over every item in a collection, and returns a collection containing only items that satisfy an include condition.
We can get single object from this array of dictionary , you can use the following code
var dict = sortedArray.filter{($0["parentId"] as! String) == "compareId"}.first
OR
let dict = sortedArray.filter{ ($0["parentId"] as! String) == "compareId" }.first
Local search filter using predicate in array of dictionary objects
with key name this code use for both swift3 and swift4,4.1 also.
func updateSearchResults(for searchController:
UISearchController) {
if (searchController.searchBar.text?.characters.count)! > 0 {
guard let searchText = searchController.searchBar.text,
searchText != "" else {
return
}
usersDataFromResponse.removeAll()
let searchPredicate = NSPredicate(format: "userName
CONTAINS[C] %#", searchText)
usersDataFromResponse = (filteredArray as
NSArray).filtered(using: searchPredicate)
print ("array = \(usersDataFromResponse)")
self.listTableView.reloadData()
}
}
Here I use CoreData And I have Array of Dictionary .
Here I am filter the key paymentToInvoice that value is invoice array then key invoiceToPeople that key contain People Dictionary then I search FirstName, lastName, Organization multiple key contain searchText.
I hope it's helps Please try this Thank You
var searchDict = dict.filter { (arg0) -> Bool in
let (key, value) = arg0
for paymentInfo in (value as! [PaymentInfo]){
let organization = (Array((value as! [PaymentInfo])[0].paymentToInvoice!)[0] as! InvoiceInfo).invoiceToPeople?.organization
let firstName = (Array((value as! [PaymentInfo])[0].paymentToInvoice!)[0] as! InvoiceInfo).invoiceToPeople?.firstName
let lastName = (Array((value as! [PaymentInfo])[0].paymentToInvoice!)[0] as! InvoiceInfo).invoiceToPeople?.lastName
return organization?.localizedStandardRange(of: searchText) != nil || firstName?.localizedStandardRange(of: searchText) != nil || lastName?.localizedStandardRange(of: searchText) != nil
}
return true
}
I have an NSMutableArray that contains String values. I have a String variable and I want to check if it is contained in the array or not.
I tried using .contains() with String but it say:
Cannot convert value of type String to expected argument type...
var mutableArray = NSMutableArray() // ["abc", "123"]
var string = "abc"
mutableArray.contains("abc") { // above error in this line
}
Multiple ways to check element existence in NSMutableArray. i.e
if mutableArray.contains("abc")
print("found")
else
print("not found")
or
if contains(mutableArray, "abc")
print("found")
or
if mutableArray.indexOfObject("abc") != NSNotFound
print("found")
If we want to check existence of element according of version of
swift
Swift1
if let index = find(mutableArray, "abc")
print(index)
Swift 2
if let index = mutableArray.indexOf("abc")
print(index)
I do still not understand why you cannot use a native Swift array, but okay.
Two possible solutions are to either use
let contains = mutableArray.contains { $0 as? String == "abc" }
or
let contains = mutableArray.containsObject("abc")
or
let contains = mutableArray.indexOfObject("abc") != NSNotFound
If you would use a native array you could simply do
var array = ["123", "abc"]
let contains = array.contains("abc")
if we have an array that contain strings for example {"houssam","hassan","taleb"}
and we have a string = "ss"
I need to return an array that return the string which contain ss, so in this case we have {"houssam","hassan"}
What is the best method to do that?
Thanks,
You can try this:
let string = "ss"
let array = ["houssam","hassan","taleb"]
let filtered = array.filter() { $0.containsString(string) }
let filterUsers:[String] = []
let users = [String] = ["houssam","hassan","taleb"]
let searchString = "ss"
filteredUsers = users.filter({( user: String) -> Bool in
let stringMatch = user.rangeOfString(searchString)
return stringMatch != nil
})
We filter the array of users and check to see if and where it contains "ss". It adds everything to the array where it found "ss" at least once.
This is my demo.
var arr: Array = ["loveyou","loveher","hateyou"]
var Newarr = arr.filter({ $0.containsString("love")})
print(Newarr)