How can I use C# to sort values numerically?

Question

I have a string that contains numbers separated by periods. When I sort it appears like this since it is a string: (ascii char order)

3.9.5.2.1.1
3.9.5.2.1.10
3.         


        

Answer 1

Since the comparison you want to do on the strings is different from how strings are normally compared in .Net, you will have to use a custom string string comparer

 class MyStringComparer : IComparer
        {
            public int Compare(string x, string y)
            {
                // your comparison logic
                // split the string using '.' separator
                // parse each string item in split array into an int
                // compare parsed integers from left to right
            }
        }

Then you can use the comparer in methods like OrderBy and Sort

var sorted = lst.OrderBy(s => s, new MyStringComparer());

lst.Sort(new MyStringComparer());

This will give you the desired result. If not then just tweak the comparer.