All elements before last comma in a string in c#

Question

How can i get all elements before comma(,) in a string in c#? For e.g. if my string is say

string s = "a,b,c,d";

then I want all the element before d i.e. before the last comma.So my new string shout look like

string new_string = "a,b,c";

I have tried split but with that i can only one particular element at a time.

Answer 1

string new_string = s.Remove(s.LastIndexOf(','));

Answer 2

If you want everything before the last occurrence, use:

int lastIndex = input.LastIndexOf(',');
if (lastIndex == -1)
{
    // Handle case with no commas
}
else
{
    string beforeLastIndex = input.Substring(0, lastIndex);
    ...
}