How do I split a string by a multi-character delimiter in C#?

You can use the Regex.Split method, something like this:

Regex regex = new Regex(@"\bis\b");
string[] substrings = regex.Split("This is a sentence");

foreach (string match in substrings)
{
   Console.WriteLine("'{0}'", match);
}

Edit: This satisfies the example you gave. Note that an ordinary String.Split will also split on the "is" at the end of the word "This", hence why I used the Regex method and included the word boundaries around the "is". Note, however, that if you just wrote this example in error, then String.Split will probably suffice.

Based on existing responses on this post, this simplify the implementation :)

namespace System
{
    public static class BaseTypesExtensions
    {
        /// <summary>
        /// Just a simple wrapper to simplify the process of splitting a string using another string as a separator
        /// </summary>
        /// <param name="s"></param>
        /// <param name="pattern"></param>
        /// <returns></returns>
        public static string[] Split(this string s, string separator)
        {
            return s.Split(new string[] { separator }, StringSplitOptions.None);
        }


    }
}

string s = "This is a sentence.";
string[] res = s.Split(new string[]{ " is " }, StringSplitOptions.None);

for(int i=0; i<res.length; i++)
    Console.Write(res[i]);

EDIT: The "is" is padded on both sides with spaces in the array in order to preserve the fact that you only want the word "is" removed from the sentence and the word "this" to remain intact.

...In short:

string[] arr = "This is a sentence".Split(new string[] { "is" }, StringSplitOptions.None);

Or use this code; ( same : new String[] )

.Split(new[] { "Test Test" }, StringSplitOptions.None)

You can use String.Replace() to replace your desired split string with a character that does not occur in the string and then use String.Split on that character to split the resultant string for the same effect.

Here is an extension function to do the split with a string separator:

public static string[] Split(this string value, string seperator)
{
    return value.Split(new string[] { seperator }, StringSplitOptions.None);
}

Example of usage:

string mystring = "one[split on me]two[split on me]three[split on me]four";
var splitStrings = mystring.Split("[split on me]");

var dict = File.ReadLines("test.txt")
               .Where(line => !string.IsNullOrWhitespace(line))
               .Select(line => line.Split(new char[] { '=' }, 2, 0))
               .ToDictionary(parts => parts[0], parts => parts[1]);


or 

    enter code here

line="[email protected][email protected]";
string[] tokens = line.Split(new char[] { '=' }, 2, 0);

ans:
tokens[0]=to
token[1][email protected][email protected]

You can do something like this:

string splitter = "is"; 
string[] array = "This is a sentence".Split(new string[] { splitter }, StringSplitOptions.None);

But usually that is not the case, we should have splitter and loop through them:

string phrase = "This is a sentence";
string[] words = phrase.Split(' ');

foreach (var word in words)
{
    System.Console.WriteLine($"<{word}>");
}

For more info, visit Microsoft website about String.Split

https://learn.microsoft.com/en-us/dotnet/csharp/how-to/parse-strings-using-split

namespace MyNamespace
{
    public static class StringHelper
    {
        public static string[] Split(this string input, string sup, StringSplitOptions options = StringSplitOptions.None)
        {
            if (input.Contains(sup))
            {
                return input.Split(new[] { sup }, options);
            }
            return new string[] { input };
        }
    }
}

Example Usage:

using System;

namespace MyNamespace
{
    class Program
    {
        static void Main()
        {
            string example = "Hello, how are you?";
            string[] result = example.Split("how");
            
            foreach (var str in result)
            {
                Console.WriteLine(str);
            }
        }
    }
}

In this example, the string "Hello, how are you?" is split by the substring "how", resulting in an array with two elements: "Hello, " and " are you?".