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How can I split a C# string based on the first occurrence of the specified character? Suppose I have a string with value: 

101,a,b,c,d

I want to split it as 

101

a,b,c,d

That is by the first occurrence of comma character.

WerWet
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Vishnu Y
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6 Answers6

263

You can specify how many substrings to return using string.Split:

var pieces = myString.Split(new[] { ',' }, 2);

Returns:

101
a,b,c,d
Bakudan
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Grant Winney
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26
string s = "101,a,b,c,d";
int index = s.IndexOf(',');
string first =  s.Substring(0, index);
string second = s.Substring(index + 1);
Arin Ghazarian
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    @pcnThird I didn't downvote but is probably because it is just code with no explanation of the method being used. – Mark Hall Feb 03 '14 at 04:25
  • @pcnThird, Don't know, though I think GrantWinney's answer is the best. – Arin Ghazarian Feb 03 '14 at 04:26
  • Actually, this one provides a fine alternative to the GrantWinney's answer for those not having access to this split method. (Those using the compact framework for exemple) – Maniz May 17 '17 at 08:38
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    Maybe because if IndexOf can't find the delimiter it returns -1. In this case, the code will not correctly split the string. It should return the entire string as first, but first will be empty (or possibly crash). – ThisGuy Sep 09 '17 at 03:45
15

You can use Substring to get both parts separately.

First, you use IndexOf to get the position of the first comma, then you split it :

string input = "101,a,b,c,d";
int firstCommaIndex = input.IndexOf(',');

string firstPart = input.Substring(0, firstCommaIndex); //101
string secondPart = input.Substring(firstCommaIndex + 1); //a,b,c,d

On the second part, the +1 is to avoid including the comma.

Pierre-Luc Pineault
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9

Use string.Split() function. It takes the max. number of chunks it will create. Say you have a string "abc,def,ghi" and you call Split() on it with count parameter set to 2, it will create two chunks "abc" and "def,ghi". Make sure you call it like string.Split(new[] {','}, 2), so the C# doesn't confuse it with the other overload.

dotNET
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3
var pieces = myString.Split(',', 2);

This won't work. The overload will not match and the compiler will reject it.

So it Must be:

char[] chDelimiter = {','};
var pieces = myString.Split(chDelimiter, 2);
Dilan
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Sierra
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1

In .net Core you can use the following;

var pieces = myString.Split(',', 2);

Returns:

101
a,b,c,d
mark_h
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