Split string with plus sign as a delimiter

Question

I have an issue with a string containing the plus sign (+). I want to split that string (or if there is some other way to solve my problem)

string ColumnPlusLevel = "+-J10+-J10+-J10+-J10+-J10";
string strpluslevel = ""; 
strpluslevel = ColumnPlusLevel; 
string[] strpluslevel_lines = Regex.Split(strpluslevel, "+");

foreach (string line in strpluslevel_lines)
{
    MessageBox.Show(line);
    strpluslevel_summa = strpluslevel_summa + line;
}   

MessageBox.Show(strpluslevel_summa, "summa sumarum");

The MessageBox is for my testing purpose.

Now... The ColumnPlusLevel string can have very varied entry but it is always a repeated pattern starting with the plus sign. i.e. "+MJ+MJ+MJ" or "+PPL14.1+PPL14.1+PPL14.1" as examples. (It comes form Another software and I cant edit the output from that software)

How can I find out what that pattern is that is being repeated? That in this exampels is the +-J10 or +MJ or +PPL14.1

In my case above I have tested it by using only a MessageBox to show the result but I want the repeated pattering stored in a string later on.

Maybe im doing it wrong by using Split, maybe there is another solution. Maybe I use Split in the wrong way.

Hope you understand my problem and the result I want.

Thanks for any advice.

/Tomas

Please post a [mcve]. You did post code, but I cannot tell *what exactly* you want to achieve. Do you like what's presented in your message boxes? If not, why not? What do you *want*? — nvoigt, Mar 29 '18 at 12:34
Please be more specific on the input and desired output; it is a bit unclear from the current formulation of the question. — Codor, Mar 29 '18 at 12:34
Why does everybody want to use Regex for simple problems that can use string method : string[] strpluslevel_lines = strpluslevel.Split(new char[] { '+'}); — jdweng, Mar 29 '18 at 12:34
What exactly is the problem with your code. What isn't working? — Jerodev, Mar 29 '18 at 12:35
You may be able to use regex to determine the shortest repeating pattern: https://stackoverflow.com/questions/28963384/finding-the-shortest-repetitive-pattern-in-a-string — user1934587390, Mar 29 '18 at 12:41

Tim Schmelter · Answer 1 · 2018-03-29T13:17:56.503

How can I find out what that pattern is that is being repeated?

Maybe i didn't understand the requirement fully, but isn't it easy as:

string[] tokens = ColumnPlusLevel.Split(new[]{'+'}, StringSplitOptions.RemoveEmptyEntries);
string first = tokens[0];
bool repeatingPattern = tokens.Skip(1).All(s => s == first);

If repeatingPattern is true you know that the pattern itself is first.

Can you maybe explain how the logic works

The line which contains tokens.Skip(1) is a LINQ query, so you need to add using System.Linq at the top of your code file. Since tokens is a string[] which implements IEnumerable<string> you can use any LINQ (extension-)method. Enumerable.Skip(1) will skip the first because i have already stored that in a variable and i want to know if all others are same. Therefore i use All which returns false as soon as one item doesn't match the condition(so one string is different to the first). If all are same you know that there is a repeating pattern which is already stored in the variable first.

Thank you very much. Can you maybe explain how the logic works in the Bool line. Might be good to know if any tweaking is needed later on. :-) — Tomas Nordström, Mar 29 '18 at 12:49

score 1 · Answer 2 · answered Mar 29 '18 at 12:34

1

You should use String.Split function :

string pattern = ColumnPlusLevel.Split("+")[0];

answered Mar 29 '18 at 12:34

Onyx Caldin

289
1
12

score 0 · Answer 3 · answered Mar 29 '18 at 12:43

...but it is always a repeated pattern starting with the plus sign.

Why do you even need String.Split() here if the pattern always only repeats itself?

string input = @"+MJ+MJ+MJ";

int indexOfSecondPlus = input.IndexOf('+', 1);
string pattern = input.Remove(indexOfSecondPlus, input.Length - indexOfSecondPlus);
//pattern is now "+MJ"

No need of string split, no need to use LinQ

score 0 · Answer 4 · answered Mar 29 '18 at 12:44

String has a method called Split which let's you split/divide the string based on a given character/character-set:

string givenString = "+-J10+-J10+-J10+-J10+-J10"'

string SplittedString = givenString.Split("+")[0] ///Here + is the character based on which the string would be splitted and 0 is the index number

string result = SplittedString.Replace("-","") //The mothod REPLACE replaces the given string with a targeted string,i added this so that you can get the numbers only from the string

Split string with plus sign as a delimiter

4 Answers4