I have string something like this "12,13" and I want to convert into array like this [12,13] in controller. I used split function it does not work.
$scope.mySplit = function(string, nb) {
var array = string.split(',');
return array[nb];
}
$scope.isChecked = function(id,matches) {
var isChecked = false;
var arr= [];
arr = $scope.mySplit(matches,0);
console.log(arr);
};
One problem might be that you did not define arr to be a variable as such: var arr = $scope.mySplit(matches,0);. Or another variable. Unless you declared it globally somewhere else.
Look at this jsfiddle that works: https://jsfiddle.net/wapp4u5g/
Related
I am still not sure about the rules of struct copy or reference.
I want to mutate a struct object while iterating on it from an array:
For instance in this case I would like to change the background color
but the compiler is yelling at me
struct Options {
var backgroundColor = UIColor.blackColor()
}
var arrayOfMyStruct = [MyStruct]
...
for obj in arrayOfMyStruct {
obj.backgroundColor = UIColor.redColor() // ! get an error
}
struct are value types, thus in the for loop you are dealing with a copy.
Just as a test you might try this:
Swift 3:
struct Options {
var backgroundColor = UIColor.black
}
var arrayOfMyStruct = [Options]()
for (index, _) in arrayOfMyStruct.enumerated() {
arrayOfMyStruct[index].backgroundColor = UIColor.red
}
Swift 2:
struct Options {
var backgroundColor = UIColor.blackColor()
}
var arrayOfMyStruct = [Options]()
for (index, _) in enumerate(arrayOfMyStruct) {
arrayOfMyStruct[index].backgroundColor = UIColor.redColor()
}
Here you just enumerate the index, and access directly the value stored in the array.
Hope this helps.
You can use use Array.indices:
for index in arrayOfMyStruct.indices {
arrayOfMyStruct[index].backgroundColor = UIColor.red
}
You are working with struct objects which are copied to local variable when using for in loop. Also array is a struct object, so if you want to mutate all members of the array, you have to create modified copy of original array filled by modified copies of original objects.
arrayOfMyStruct = arrayOfMyStruct.map { obj in
var obj = obj
obj.backgroundColor = .red
return obj
}
It can be simplified by adding this Array extension.
Swift 4
extension Array {
mutating func mutateEach(by transform: (inout Element) throws -> Void) rethrows {
self = try map { el in
var el = el
try transform(&el)
return el
}
}
}
Usage
arrayOfMyStruct.mutateEach { obj in
obj.backgroundColor = .red
}
For Swift 3, use the enumerated() method.
For example:
for (index, _) in arrayOfMyStruct.enumerated() {
arrayOfMyStruct[index].backgroundColor = UIColor.redColor()
}
The tuple also includes a copy of the object, so you could use for (index, object) instead to get to the object directly, but since it's a copy you would not be able to mutate the array in this way, and should use the index to do so. To directly quote the documentation:
If you need the integer index of each item as well as its value, use
the enumerated() method to iterate over the array instead. For each
item in the array, the enumerated() method returns a tuple composed of
an integer and the item.
Another way not to write subscript expression every time.
struct Options {
var backgroundColor = UIColor.black
}
var arrayOfMyStruct = [Options(), Options(), Options()]
for index in arrayOfMyStruct.indices {
var option: Options {
get { arrayOfMyStruct[index] }
set { arrayOfMyStruct[index] = newValue }
}
option.backgroundColor = .red
}
I saw this method in some code and it seems to be working
for (var mutableStruct) in arrayOfMyStruct {
mutableStruct.backgroundColor = UIColor.redColor()
}
I have latsArr and LongsArr filled from firebase automatically.
I want to populate latsAndLongsArray in viewDidLoad function. How can I do that?
var latsArr = [1111.0,2222.0,333.0]
var longsArr = [444.0,555.0,666.0]
var latsAndLongs = [[111.0,444.0],[222.0,555.0],[333.0,666.0]]
Use the zip(_:_:) and map(_:) methods combined to get the expected result:
let latsAndLongs = zip(latsArr, longsArr).map { [$0.0, $0.1] }
var latsAndLongs = zip(latsArr, longsArr).map({[$0.0, $0.1]})
One option (which uses tuples instead of arrays) is to use zip.
var latsArr = [1111.0,2222.0,333.0]
var longsArr = [444.0,555.0,666.0]
var latsAndLongs = zip(latsArr, longsArr)
// latsAndLongs == [(1111.0, 444.0), (2222.0, 555.0), (333.0, 666.0)]
I have a tableView with different kinds of infos, each coming from a different array.
I could not work with dictionaries because then the list would have been unordered and I could not work with classes, because I have different lists with all kinds of dynamic entries (properties are always different etc.)
Here my problem:
I want to implement a search function. But when I use the filter function for one array, it changes of course based on the implemented condition but the other 5 stay the same => I can't reload the tableView because the array information does not match anymore ...
Here the arrays:
var categoryItemUIDs = [String]()
var categoryItemDescriptions = [String]()
var categoryItemLfdNrs = [Int]()
var categoryGivenOuts = [Bool]()
var categoryGivenTos = [String]()
var categoryGivenAts = [String]()
var categoryStorageLocations = [String]()
In the tableView(cellForRowAtIndexPath method):
cell.customTextLabel?.text = categoryItemLfdNrs[indexPath.row]
cell.customDetailTextLabel.text = categoryItemDescriptions[indexPath.row]
Here the searchBar(textDidChange) method:
self.categoryItemDescriptions.filter { $0.lowercased().contains(searchText.lowercased()) }
Now I get an array back with reduced size, but all the other arrays stay the same... Is there maybe another way to avoid this problem? I already tried type aliases but it did not work out.
I would appreciate any help!
Kind regards,
When it goes to such a big count of arrays, the time for your specific type comes.
The simple solution is to create something like
struct Category {
var uid: String
var description: String
// ...
var storageLocation: String
}
The you have simply something like
var items: [Category]
And you can still do simple things in cellForRowAtIndexPath
cell.customTextLabel?.text = items[indexPath.row].lfdnrs
cell.customDetailTextLabel.text = items[indexPath.row].description
And only 1 array to filter
items.filter { $0.description.lowercased().contains(searchText.lowercased()) }
So overall advice is to solve different problem (here I suggested the solution of the having your data in the app problem instead of filtering multiple arrays with one condition)
try
var categoryItemUIDs = ["aaa","bbb","ccc"]
var categoryItemDescriptions = ["ddd","eee","fff"]
var categoryItemLfdNrs = [0,1,2]
struct data {
var id = ""
var desc = ""
var item = 0
init(id :String, desc:String, item:Int)
{
self.id = id
self.desc = desc
self.item = item
}
}
//var cat = [data]()
//for i in 0..<categoryItemUIDs.count {
// cat.append(data(id:categoryItemUIDs[i], desc:categoryItemDescriptions[i],item:categoryItemLfdNrs[i] ))
//}
//more swift
let cat = (0..<categoryItemUIDs.count).map { (i) -> data in
return data(id:categoryItemUIDs[i], desc:categoryItemDescriptions[i],item:categoryItemLfdNrs[i] )
}
print (cat)
let catFilter = cat.filter { $0.id == "aaa" }
print (catFilter)
For example, I have an array like var myArray = ['player_static.png', 'player_run0.png', 'player_run1.png', 'player_run2.png', 'player_jump0.png', 'player_jump1.png']
Is there any simple way to get only the "player_runX.png" images?
You can use filter to get all elements that hasPrefix("player_run"):
let myArray = ["player_static.png", "player_run0.png", "player_run1.png", "player_run2.png", "player_jump0.png", "player_jump1.png"]
let playerRuns = myArray.filter{$0.hasPrefix("player_run")}
print(playerRuns) //["player_run0.png", "player_run1.png", "player_run2.png"]
One way to do this would be to iterate over the array and retrieve the elements that match the pattern. A very quick sample would be something like this:
var myArray = ["player_static.png", "player_run0.png", "player_run1.png", "player_run2.png", "player_jump0.png", "player_jump1.png"]
func getSubArray(array:[String],prefix:String) -> [String]
{
var newArray = [String]()
for img in array
{
if img.substringToIndex(img.startIndex.advancedBy(prefix.characters.count)) == prefix
{
newArray.append(img)
}
}
return newArray
}
var test = getSubArray(myArray, prefix: "player_run")
var contact = { varWorkExperiences: [{ Experience: "aaa" },Experience: "bbb"}] };
I have a structure like this. I can use push method like this:
contact.varWorkExperiences.push({ Experience: "ccc"});
but I want to do this paramaticly
I cant do this:
var x = "Experience";
contact.varWorkExperiences.push({ x: "ccc"});
How can I solve this? I have to use push method in function but I can't pass attribute as a parameter.
var x = "Experience";
var obj = {};
obj[x] = "ccc";
contact.varWorkExperiences.push(obj);