In Javascript, you can use splice to remove a specific item.
Ex:-

var items =[1,4,6,13,67];
var itemToBeRemoved = 13; 
items.splice(items.indexOf(itemToBeRemoved),1); // find the index of item and delete "1" item
console.log(items);

In C# , you can use RemoveAt() method.

static void Main()
 {
 List<int> items= new List<int>(){1,2,3,5,13,64};
 int itemToBeRemoved = 5;
        items.RemoveAt(items.IndexOf(itemToBeRemoved));
 Console.WriteLine(string.Join(",", items));
 }