Get index of object from array of dictionary with key value - ios

Question

I have one array with dictionary.
Now i want to get index number of object with particular key value.
Like key = "xyz" and value = "abc".
I need index of object having above matching in dictionary.
{
Id = 20085;
IsNew = 1;
Title = Circular;
},
{
Id = 20088;
IsNew = 0;
Title = Query;
},
{
Id = 20099;
IsNew = 1;
Title = Blog;
},
{
Id = 20104;
IsNew = 1;
Title = News;
},
{
Id = 20172;
IsNew = 1;
Title = AssignTask;
},
{
Id = 20183;
IsNew = 1;
Title = Gallery;
},
{
Id = 20204;
IsNew = 1;
Title = Poll;
},
{
Id = 20093;
IsNew = 1;
Title = Assignment;
},
{
Id = 20209;
IsNew = 1;
Title = Activity;
},
{
Id = 20130;
IsNew = 1;
Title = Behaviour;
},
{
Id = 20180;
IsNew = 1;
Title = Result;
}
now i need index of object with having key = "Title" and value = "result"

Answer 1

You can use indexOf(_:) for this:
let index = array.indexOf{ $0["key"] == value }
In Swift 3.0, it's been renamed to index(Where:):
let index = array.index{ $0["key"] == value }
You can see this in action here.

Answer 2

Here is what you should be doing after using a json parser
let array:NSArray = [
[
"Id": 20130,
"IsNew": 1,
"Title":"Behaviour"
],
[
"Id": 20180,
"IsNew": 1,
"Title":"Result"
]]
let k = array as Array
let index = k.indexOf {
if let dic = $0 as? Dictionary<String,AnyObject> {
if let value = dic["Title"] as? String
where value == "Result"{
return true
}
}
return false
}
print(index) // index

Answer 3

I'd start with mapping the id values to an array, then getting the index of the id you're looking for.
func getIndexOf(itemID: Int) -> Int {
//Map out all the ids from the array of dictionaries into an array of Integers
let keysArray = dictionaries.map { (dictionary) -> Int in
return dictionary.value(forKey: "Id")
}
//Find the index of the id you passed to the functions
return keysArray.index(of: itemID)
}

Answer 4

other mainstream way to do this
func getIndex(of key: String, for value: String, in dictionary : [[String: Any]]) -> Int{
var count = 0
for dictElement in dictionary{
if dictElement.keys.contains(key) && dictElement[key] as! String == value{
return count
}
else{
count = count + 1
}
}
return -1
}
var sampleDict : [[String:Any]] = [
[
"Id" : 20130,
"IsNew" : 1,
"Title" : "Behaviour"
],
[
"Id" : 20130,
"IsNew" : 1,
"Title" : "Result"
],
]
let index = getIndex(of: "Title", for: "Result", in: sampleDict)
print(index)
This will print 1.

Answer 5

This answer is for the Swift 5.2 and above versions.
arr.append(["Title":titleName,"ID":1,"Result":true])
arr.append(["Title":titleName,"ID":2,"Result":true])
arr.append(["Title":titleName,"ID":3,"Result":true])
arr.append(["Title":titleName,"ID":4,"Result":true])
This is an array of dictionary format. And if you want to find an index of an object where ID == 3
func findIndex(Id : Int ) -> Int? {
guard let index = arr.firstIndex(where: {
if let dic = $0 as? Dictionary<String,AnyObject> {
if let value = dic["ID"] as? Int, value == Id {
return true
}
}
return false
}) else { return nil }
return index
}
let myIndex = findIndex(3)
self.arr.insert( ["Title":titleName,"ID":10,"Result":true]) at: myIndex)