How to truncate a string in .net

Question

Given the string: /Projects/Multiply_Amada/MultiplyWeb/Shared/Home.aspx

I want to remove all trailing characters after the third /, such that the result is: /Projects/Multiply_Amada/

I would like to do this without using Split or Charindex.

What do you mean with `without use (Split/Charindex)`? How should a substring be removed without knowing the index where to start? — Tim Schmelter, Jun 03 '11 at 13:27
Care to give a reason for your requirements? Otherwise it should be posted on http://codegolf.stackexchange.com/ — DarthJDG, Jun 03 '11 at 16:15

score 2 · Answer 1 · answered Jun 03 '11 at 13:40

2

OK, your requirements are a bit tough. So, what about this:

string RemoveAfterThirdSlash(string str)
{
    return str.Aggregate(
            new {
                sb = new StringBuilder(),
                slashes = 0
            }, (state, c) => new {
                sb = state.slashes >= 3 ? state.sb : state.sb.Append(c),
                slashes = state.slashes + (c == '/' ? 1 : 0)
            }, state => state.sb.ToString()
        );
}

Console.WriteLine(RemoveAfterThirdSlash("/Projects/Multiply_Amada/MultiplyWeb/Shared/Home.aspx"));

answered Jun 03 '11 at 13:40

Mormegil

7,955
4
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how can use aggregate function for string.. it will showing error ('string' does not contain a definition for 'Aggregate' and no extension method 'Aggregate' accepting a first argument of type 'string' could be found (are you missing a using directive or an assembly reference?)string RemoveAfterThirdSlash(string str) Line 65: { Line 66: return str.Aggregate( Line 67: new Line 68: { – Anto Jun 03 '11 at 14:02
Add the System.Linq namespace – markpsmith Jun 03 '11 at 14:23

score 1 · Answer 2 · answered Jun 03 '11 at 13:35

1

string str = "/Projects/Multiply_Amada/MultiplyWeb/Shared/Home.aspx";

string newStr = str.SubString(0,24);

I suppose that answers your question!

answered Jun 03 '11 at 13:35

markpsmith

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no cant use substring it will affect in server link..so pls give another solution – Anto Jun 03 '11 at 13:52

score 0 · Answer 3 · answered Jun 03 '11 at 13:43

This code acheives what you need, but I would prefer doing it in 1 lines using the available .NET methods

string str = "/Projects/Multiply_Amada/MultiplyWeb/Shared/Home.aspx";

int index = 0;
int slashCount = 0;

for (int i = 0; i < str.Length; i++)
{
    if (str[i] == '/' && slashCount < 3)
    {
        index = i;
        slashCount++;
    }
}

string newString = str.Substring(index + 1);

score 0 · Answer 4 · answered Jun 03 '11 at 13:47

Because you are working with paths, you can do this:

    Public Function GetPartialPath(ByVal input As String, ByVal depth As Integer) As String

        Dim partialPath As String = input
        Dim directories As New Generic.List(Of String)

        Do Until String.IsNullOrEmpty(partialPath)
            partialPath = IO.Path.GetDirectoryName(partialPath)
            directories.Add(partialPath)
        Loop

        If depth > directories.Count Then depth = directories.Count

        Return directories.ElementAt(directories.Count - depth)

    End Function

Not tested.

How to truncate a string in .net

4 Answers4

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