Check if string contains string from an array then use that in LastIndexOf method

Question

I want to check if my input string contains one of 3 strings and use it later on. Here's what I have so far:

// this is just an example of 1 out of 3 possible variations
string titleID = "document for the period ended 31 March 2014";

// the array values represent 3 possible variations that I might encounter
string s1 = "ended ";
string s2 = "Ended ";
string s3 = "Ending ";
string[] sArray = new [] { s1, s2, s3};

if(sArray.Any(titleID.Contains))
{
      TakeEndPeriod = titleID.Substring(titleID.LastIndexOf(string));
}

I want to check which string from the array has the Contains method found and use exactly that one in the LastIndexOf method. Am I on the right track here?

EDIT:

Sorry for any confusion here. titleID.LastIndexOf(string) <- the string is just a dummy and it represents what I'd like to achieve here. I was previously using the Contains method to check only for 1 of the values f.eg. if(titleID.Contains"ended ") and then I'd do titleID.LastIndexOf("ended "). I could have 3 separate blocks each based on "ended", "Ended" or "Ending" using each one in the LastIndexOf method but I want to make it more simple and flexible towards the input, otherwise I'd have 3 times more code and I would like to avoid that.

EDIT NR 2:

How would I achieve the same result if I couldn't use System.Linq? Cause the solution provided here works when I test it in the IDE, but the software itself which will be using this code doesn't give me the possibility declare "using System.Linq". I'm thinking I need to have something like System.Linq.Enumerable.FirstOrDefault.

You need to loop on the sArray array, checking each string against the title to see which one is found. — Lasse V. Karlsen
– Lasse V. Karlsen, Commented Jun 26, 2014 at 7:34
@user2310920 you can remove comments if you want - to the right of your own comments there's a small delete button (you'll see it if you hover your comment) — default
– default, Commented Jun 26, 2014 at 8:43

Stuart · Accepted Answer · 2014-06-26 07:47:41Z

3

        // this is just an example of 1 out of 3 possible variations
        string titleID = "document for the period ended 31 March 2014";

        // the array values represent 3 possible variations that I might encounter
        string s1 = "ended ";
        string s2 = "Ended ";
        string s3 = "Ending ";
        string[] sArray = new [] { s1, s2, s3};

        var stringMatch = sArray.FirstOrDefault(titleID.Contains);
        if (stringMatch != null)
        {
            TakeEndPeriod = titleID.Substring(titleID.LastIndexOf(stringMatch));
        }

edited Jun 26, 2014 at 7:47

answered Jun 26, 2014 at 7:34

Stuart

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4 Comments

Sayse Over a year ago

+1 As a note for the OP, if none are found then valForLater will be null (in this circumstance)

Typist Over a year ago

And last item in the text. it can be one of the string in the array

Stuart Over a year ago

He wants the string to pass into LastIndexOf not the index in the array

escape_artist Over a year ago

@StuartCampbell that's exactly what I want to achieve here. The idea is that after I do that I'm parsing the date into a custom format, so it's important I get the position after one of the strings from the array. UPDATE! It works! Thx!!!

Tolga Evcimen · Accepted Answer · 2014-06-26 07:55:13Z

0

this should do it.

// this is just an example of 1 out of 3 possible variations
string titleID = "document for the period ended 31 March 2014";

string s1 = "ended ";
string s2 = "Ended ";
string s3 = "Ending ";
string[] sArray = new [] { s1, s2, s3};

var maxLastIndex = -2; 
foreach(var s in sArray)
{
    var lastIndex = titleID.LastIndexOf(s);
    if(lastIndex > maxLastIndex)
        maxLastIndex = lastIndex;
}

/// if maxLastIndex is still -1 it means no matching elements exist in the string.

edited Jun 26, 2014 at 7:55

answered Jun 26, 2014 at 7:46

Tolga Evcimen

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2 Comments

Sayse Over a year ago

maxLastIndex can never finish as -2 since LastIndexOf will return -1

Tolga Evcimen Over a year ago

There is no loop that needs to be ended with that -1 constraint.

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