Better way to find index of item in ArrayList?

Question

For an Android app, I have the following functionality

private ArrayList _categories; // eg [\"horses\",\"camels\"[,etc]]

private int getCateg         


        

Answer 1

the best solution here

class Category(var Id: Int,var Name: String)
arrayList is Category list
val selectedPositon=arrayList.map { x->x.Id }.indexOf(Category_Id)
spinner_update_categories.setSelection(selectedPositon)

Answer 2

The best way to find the position of item in the list is by using Collections interface,

Eg,

List<Integer> sampleList = Arrays.asList(10,45,56,35,6,7);
Collections.binarySearch(sampleList, 56);

Output : 2