Generic Methods

Question

Hi All I just started learning generics and we were asked to create a generic method in a class that accepts an array and an individual object of the same type. The method should remove duplicates in the array and replace the duplicate with a with a default or elimination value represented by the second parameter. We then have to create an application that will implement this using 3 different types that have different lengths. I've seen many ways of doing this but since I am still very new at this I don't know which one to apply to my problem. Any help will be appreciated.

Vulpes · Answer

This is how I'd do it though I've just done it for one type - I'll leave you to do it for two other types: using System; using System.Collections.Generic; class Program { static void Main() { MyClass mc = new MyClass(); int[] ia = {1 1 3 4 4 6 1 7 3 8}; mc.MyMethod(ia 2); // use 2 as default value // check it worked foreach(int i in ia) Console.Write({0}  i); Console.WriteLine(); Console.ReadKey(); } } class MyClass { public void MyMethod (T[] arr T defValue) { if (arr == null || arr.Length List dupList = new List (); // find indices of all duplicates for(int i = 1; i { if(Array.IndexOf(arr arr[i] 0 i) > -1) dupList.Add(i); } // if there are any duplicates replace them with default value if (dupList.Count == 0) return; for(int i = 0; i { arr[dupList[i]] = defValue; } } } As expected the output is: 1 2 3 4 2 6 2 7 2 8 Notice that there's no need to specify 'int' as the type parameter when you call MyMethod because the compiler can infer this from the types of the arguments.

Vulpes · Answer

Yes you could eliminate that line. In fact if you don't need to know which items are duplicates you could simplify the whole method to just this: public void MyMethod (T[] arr T defValue) { if (arr == null || arr.Length for(int i = 1; i { if(Array.IndexOf(arr arr[i] 0 i) > -1) arr[i] = defValue; } }

theLizard · Answer

// if there are any duplicates replace them with default value if (dupList.Count == 0) return; for(int i = 0; i { arr[dupList[i]] = defValue; } No need to do this if (dupList.Count == 0) return; because if dupList count is 0 then it will fall through the loop test

Avuya Mxoli · Answer

Thank you so much Vulpes that helped me alot!!