i have a struct array that i want "break up" into smaller arrays that can be called as needed or at least figure out how i can map the items needed off one text value.
the struct:
struct CollectionStruct {
var name : String
var description : String
var title : String
var image : PFFile
var id: String
}
and the array made from the struct
var collectionArray = [CollectionStruct]()
var i = 0
for item in collectionArray {
print(collectionArray[i].name)
i += 1
}
printing partArray[i].name gives the following result:
pk00_pt01
pk00_pt02
pk00_pt03
pk01_pt01
pk01_pt02
pk01_pt03
pk01_pt04
pk01_pt05
pk01_pt06
pk01_pt07
pk01_pt08
this is just some test values but there could be thousands of entries here so i wanted to filter the entire array just by the first 4 characters of [i].name i can achieve this by looping through as above but is this achievable using something like .map?
I wanted to filter the entire array just by the first 4 characters of
[i].name
You can achieve this by filtering the array based on the substring value of the name, as follows:
let filteredArray = collectionArray.filter {
$0.name.substring(to: $0.name.index($0.name.startIndex, offsetBy: 4)).lowercased() == "pk00"
// or instead of "pk00", add the first 4 characters you want to compare
}
filteredArray will be filled based on what is the compared string.
Hope this helped.
If you want to group all data automatically by their name prefix. You could use a reducer to generate a dictionary of grouped items. Something like this:
let groupedData = array.reduce([String: [String]]()) { (dictionary, myStruct) in
let grouper = myStruct.name.substring(to: myStruct.name.index(myStruct.name.startIndex, offsetBy: 4))
var newDictionart = dictionary
if let collectionStructs = newDictionart[grouper] {
newDictionart[grouper] = collectionStructs + [myStruct.name]
} else {
newDictionart[grouper] = [myStruct.name]
}
return newDictionart
}
This will produce a dictionary like this:
[
"pk00": ["pk00_pt01", "pk00_pt02", "pk00_pt03"],
"pk01": ["pk01_pt01", "pk01_pt02", "pk01_pt03", "pk01_pt04", "pk01_pt05", "pk01_pt06", "pk01_pt07"],
"pk02": ["pk02_pt08"]
]
Not sure if i am understanding you correctly but it sounds like you are looking for this...
To create a new array named partArray from an already existing array named collectionArray (that is of type CollectionStruct) you would do...
var partArray = collectionArray.map{$0.name}
Related
I am trying to filter the array 'employee_name' consisting of NaNs and one string element, to exclude any element BUT the string. The context is that I have a spreadsheet containing employee's birth dates, and I'm sending an email notification in case there's a birthday two days from today. My variables look like this:
var ss = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Employees');
var range = ss.getRange(2, 1, ss.getLastRow()-1, 1); // column containing the birth dates
var birthdates = range.getValues(); // get the `values` of birth date column
var today = new Date ();
var today = new Date(today.getTime());
var secondDate = new Date(today.getTime() + 48 * 60 * 60 * 1000);
var employee_name = new Array(birthdates.length-1);
And the loop:
for (var i=0;i<=birthdates.length-1;i=i+1){
var fDate = new Date(birthdates[i][0]);
if (fDate.getDate() == secondDate.getDate() &&
fDate.getMonth() == secondDate.getMonth()){
//define variables for outgoing email
for (var j=0; j<=birthdates.length-1;j=j+1){
employee_name[j] = [NaN];
}
employee_name[i] = ss.getRange(i+2,6);
employee_name[i] = employee_name[i].getValues();
}
}
after which the array in question looks like this
Logger.log(employee_name);
[[[Mia-Angelica]], [NaN], [NaN], [NaN], ..., [NaN]]
I have already tried the filter(Boolean), but this isn't working:
employee_name_filtered = employee_name.filter(Boolean);
Logger.log(employee_name_filtered);
returns [[[Mia-Angelica]], [NaN], [NaN], [NaN], ..., [NaN]].
I have also tried filling the non-string array entries with numeric values (instead of NaN) and then apply
employee_name_filtered = employee_name.filter(isFinite);
Logger.log(employee_name_filtered);
returns [[1.0], [2.0], [3.0], ..., [72.0]], so this filter method is working, but then I would need the 'inverse' of that because I want to keep the string.
I need the array within array to store the values at the position of the counter variable where the condition's met (similar to How to store data in Array using For loop in Google apps script - pass array by value).
This is my first time posting a question on SO, so if I overlooked any 'rules' about posting, just let me know and I will provide additional info.
Any help will be appreciated!
EDIT:
what I would like to receive in the end is simply
[[Mia-Angelica]].
The array you are using a 2 dimensional array - meaning it's an array of arrays so the filter method you are using cannot be applied in the same manner.
For this, I suggest you try the below snippet.
function cleanArray() {
var initialArray = [
['Mia-Angelica'],
['Space'],
['2'],
[NaN],
[NaN],
[NaN],
[NaN]
];
var finalArray = [];
for (let i = 0; i < initialArray.length; i++) {
var midArray = initialArray[i].filter(item => (Number.isFinite(item) && item.id !== 0) || !Object.is(item, NaN));
finalArray.push(midArray);
}
console.log(finalArray.filter(item => item != ''));
}
Note
Please bear in mind that getValues will return an Object[][] which is a two-dimensional array of values.
Reference
Apps Script Range Class;
Array.prototype.filter().
I'm trying to filter a set of objects based on values in one of their elements based on another array. I've got it working with filter just fine if the search is "OR" - it returns give me all objects for which at least one of the strings in the search array is found.
But I can't figure out how to make it work as an AND search - returning only the objects that match ALL of the strings in the search array.
Example:
struct Schedule {
let title: String
let classTypes: [String]
}
let schedule1 = Schedule(title: "One", classTypes: ["math","english","chemistry","drama"])
let schedule2 = Schedule(title: "Two", classTypes: ["pe","math","biology"])
let schedule3 = Schedule(title: "Three", classTypes: ["english","history","math","art"])
let schedules = [schedule1, schedule2, schedule3]
let searchArray = ["math", "english"]
//works for OR - "math" or "english"
var filteredSchedules = schedules.filter { $0.classTypes.contains(where: { searchArray.contains($0) }) }
I'd like to find a way for it to use the same search array
let searchArray = ["math", "english"]
But only return items 1 & 3 - as they both have BOTH math and english in the list.
There are good examples of AND conditions when the AND is across different search criteria: car type and colour - but I've been unable to find an example where the criteria are dynamically based on items in an array. For context, I could have dozens of schedules with 20+ class types.
You can work with a Set, isSubset will return true if the schedules element contains all elements of the searchSet
let searchSet = Set(searchArray)
var filteredSchedules = schedules.filter { searchSet.isSubset(of: $0.classTypes) }
As suggested by #LeoDabus it might be worth changing the type of classTypes to Set instead of arrays (if order doesn't matter) since they seems to be unique and then the filtering can be done in the opposite way without the need to convert searchArray each time
var filteredSchedules = schedules.filter { $0.classTypes.isSuperset(of: searchArray) }
I have a tableView(purchases cart), which include magazines in multiple sections. In section, we can see cells with stuff from magazine. In the cell, I did display UILabel(price), UILabel(count) and UILabel with summary price (item * count) in one cell. Also, we can see two buttons (plus and minus), for changing count of item. Example -
var count: Float = Float(cell.countLabel.text!)!
guard Int(count) > 1 else { return }
var shortPrice = cell.newPrice.text
shortPrice?.removeLast(2)
let floatPrice = Float(shortPrice!)
count -= 1
let newSumShortPrice = floatPrice! * count
cell.countLabel.text = String(Int(count))
cell.summPrice.text = "\(newSumShortPrice) ₽"
But changes didn't work with an array.
The strcuct of my model -
struct ViewModel {
var name: String?
var offers: [Offers]?
}
struct Offers : Mappable {
var count : Int?
var fullPrice : String?
var shortPrice : String?
}
var purchasesViewModel = [PurchaseList.Fetch.ViewModel]()
I know, that I must pass changed data (count) to my array and use method tableView.reloadData(). But I can't, because I don't know how to do that.
How I can transfer new count value (check struct Offers) to array purchasesViewModel?
You can go to the index of the array and delete the particular data(old data) from purchasesViewModel and recreate new data and insert it on that index. I hope this will work.
I have a dictionary of prices and quantities. I am getting updates on the price and values multiple times in a second so I don't want to store them in an array because dictionary are much faster.
let mainPriceValDict = [Double:Double]()
The data is coming in as an array of JSON so I am using codable to parse the JSON and put it into a dictionary. When I use the data, it needs to be sorted in ascending and/or descending order because I am looping through each price in order to get to a certain total quantity. The format that the array is in that I am looping through is as follows:
let loopingArray = [PriceQuantityEntry]()
struct PriceQuantityEntry {
let price : Double
let size : Double
}
I want to sort the prices which are the keys in the dictionary above and convert them into an array of PriceQuantityEntry. What is the best way to do this? In ascending and deciding order. I have tried first getting all the keys sorted and then grabbing associated values and putting them into the array in order but this seems like more processing than this task actually requires.
I think the best way to do this would be to put a custom initializer in the struct to convert the dictionary value to a value of type PriceQuantityEntry but I am not exactly sure how that would work with the sorting.
This is what I am currently doing to get it to work. I just feel like there is a more efficient way for it to be done. If you feel like I should keep the structure as an array instead of converting it to a dict, let me know.
loopingArray = self.mainPriceValDict.sorted { $0.0 < $1.0 }.map { PriceQuantityEntry(price: $0.0, size: $0.1) }
If you are getting a lot of updates to individual entries, both a dictionary and an array may cause memory copies of the whole memory structure every time an entry is changed.
I would suggest using objects (classes) instead of structures. This will allow you to use both an array and a dictionary to reference the object instances. The dictionary will provide direct access for updates and the array will allow sequential processing in forward or backward order.
[EDIT] Example:
class PriceQuantityEntry
{
static var all:[PriceQuantityEntry] = []
static var prices:[Double:PriceQuantityEntry] = [:]
var price : Double
var size : Double
init(price:Double, size:Double)
{
self.price = price
self.size = size
PriceQuantityEntry.all.append(self)
// PriceQuantityEntry.all.resort() // on demand or when new prices added
PriceQuantityEntry.prices[price] = self
}
class func update(price:Double, with size:Double)
{
if let instance = PriceQuantityEntry.prices[price]
{ instance.size = size }
else
{
let _ = PriceQuantityEntry(price:price, size:size)
PriceQuantityEntry.resort()
}
}
class func resort()
{
PriceQuantityEntry.all.sort{$0.price < $1.price}
}
}
// if adding multiple initial entries before updates ...
let _ = PriceQuantityEntry(price:1, size:3)
let _ = PriceQuantityEntry(price:1.25, size:2)
let _ = PriceQuantityEntry(price:0.95, size:1)
PriceQuantityEntry.resort()
// for updates ...
PriceQuantityEntry.update(price:1, with: 2)
// going throug list ...
var count:Double = 0
var total:Double = 0
var quantity:Double = 5
for entry in PriceQuantityEntry.all
{
total += min(entry.size,quantity-count) * entry.price
count = min(quantity,count + entry.size)
if count == quantity {break}
}
I have a query that builds a Struct array from some objects. I want to append multiple of these structs into a single array so that i can use it populate a collectionview that is nested inside a collectionview. Im not sure this is the best idea but its all I've got a the moment.
So my Struct is:
struct CollectionStruct {
var name : String
var description : String
var title : String
var image : PFFile
var id: String
}
In my viewcontroller the variable to hold the struct is thus:
var packArray : [CollectionStruct] = []
var partArray : [CollectionStruct] = []
var packId = ""
So below what I'm doing is using an item of the previously created packArray to query the DB and build my partArray. Because i want to do this multiple times and append the partArray into a larger parent array i was thinking of using a for loop like:
var i = 0
for item in self.packArray as [AnyObject] {
self.packId = self.packArray[i].id
BuildArray.buildArrayFromQuery(queryForCollection: "Part", selectedPackID: self.packId, delegateSender: "DownloadPart", completeBlock: { (result) in
self.partArray = result
// append this to an array of partArray????
})
}
I don't even know where to start with this. Is it a bad idea?
essentially what i thought was to call this parent array in cellforitem maybe something like:
innerCell.imageCell.image = parentArray[indexPath.item].partArray[indexPath.item].image
but i could be way off.
----- EDIT -----
so i can use a multidimensional array inside the closure once self.partArray is set:
self.partArray = result
var parentArray = [[self.partArray]]
parentArray.append([self.partArray])
but this is unusable outside the closure. How to declare this multidimensional array before self.partArray is set?
------- EDIT -------
Looking into globals for this at the moment.
class GlobalPartArray {
private init() { }
static let sharedInstance = GlobalPartArray()
var globalPartArray = [CollectionStruct]()
}
class GlobalParentArray {
private init() { }
static let sharedInstance = GlobalParentArray()
var globalParentArray = [[GlobalPartArray]]()
}
then inside closure:
GlobalPartArray.sharedInstance.globalPartArray = result
//can not convert [CollectionStruct] to [GlobalPartArray]
GlobalParentArray.sharedInstance.globalParentArray.append(GlobalPartArray.sharedInstance.globalPartArray)
but it throws an error when trying to convert. I obviously need to convert this data somehow before appending to the GlobalParentArray.