How To Filter Array Using Element in Another Array in Swift?
this seems to be a theme today :) building on another great answer, I would suggest using the intersect(_:)
method on a Set
:
let toBeFiltered = ["star0", "star2", "star1", "star0", "star3", "star4"]
let theFilter = ["star1", "star3"]
let filtered = Set(toBeFiltered).intersect(theFilter)
// => ["star1", "star3"] of type Set<String>
// ...if you actually need an array, you can get one using Array(filtered)
Use Set Operations
Set(toBeFiltered).intersection(Set(theFilter))
Read more: https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/CollectionTypes.html
You can also filter Struct array as well
struct myStruct
{
var userid:String;
var details:String;
init() {
userid = "default value";
details = "default";
}
};
var f1 = myStruct();
f1.userid = "1";
f1.details = "Good boy";
var f2 = myStruct();
f2.userid = "2";
f2.details = "Bad boy";
var f3 = myStruct();
f3.userid = "3";
f3.details = "Gentleman";
var arrNames1:Array = [f1,f3];
var arrNames2:Array = [f3,f1,f2];
let filteredArrayStruct = arrNames1.filter( { (user: myStruct) -> Bool in
return arrNames2.contains({ (user1: myStruct) -> Bool in
return user.userid == user1.userid;
})
})
print(filteredArrayStruct)
For Set you must conforms the Hashable protocol
class mytestclass: Hashable
{
var userid:Int ;
var details:String;
var hashValue: Int {
return self.userid
}
init(userid: Int, details:String)
{
self.userid = userid;
self.details = details;
}
}
func ==(lhs: mytestclass, rhs: mytestclass) -> Bool {
return lhs.userid == rhs.userid
}
var t1 = mytestclass(userid: 1,details: "Good boy");
var t2 = mytestclass(userid: 2,details: "bad boy");
var t3 = mytestclass(userid: 3,details: "gentle man");
var classArrayNames:Set<mytestclass> = [t1,t2];
var classArrayNames2:Set<mytestclass> = [t3,t1,t2];
let result = Set(classArrayNames).intersect(classArrayNames2)
let toBeFiltered = ["star0", "star2", "star1", "star0", "star3", "star4"]
let theFilter = ["star1", "star3"]
let filtered = toBeFiltered.filter(theFilter.contains)