sorting an arraylist c#|searching an arraylist in C#|Binarysearch in arrayList in C#| sorting and searching an arraylist in C#|

We use Sort() method for sorting an arraylist. And once sorted, arraylist can be searched by BinarySearch().

Following example demonstrates these functionality

        private void SortAndSearchArrayList()
        {
            string OriginalStr="";
            string AfterSortingStr="";
            ArrayList ArrList = new ArrayList();
            ArrList.Add(21);
            ArrList.Add(30);
            ArrList.Add(25);
            ArrList.Add(22);
            ArrList.Add(20);
            ArrList.Add(35);
            ArrList.Add(24);
 
            foreach(int i in ArrList)
            {
                OriginalStr = OriginalStr + i + " ";
            }
 
            //Sort
            ArrList.Sort();
            foreach (int i in ArrList)
            {
                AfterSortingStr = AfterSortingStr + i + " ";
            }
 
            //Searching-suppose you want to find out th eindex of 22
            MessageBox.Show("Index of 22 is " + ArrList.BinarySearch(22));
        }

value of OriginalStr = 21 30 25 22 20 35 24
value of AfterSortingStr = 20 21 22 24 25 30 35

Although An arraylist can contains objects of any type within the same list, when sorting and searching a list , it is very important for those objects to be comparable. for example above program would have generated an exception if the list had included a string.