string.Split() / string.Join()

// Splits the string by the specified delimiter and returns a string array.
string.Split(char separator)
string.Split(string separator)
string.Split(char[] separators)

// Joins the elements of a collection with the specified separator and returns a string.
string.Join(string separator, IEnumerable<string> values)
string.Join(string separator, string[] values)

using System;

// Use Split() to split a comma-separated string.
string csvRow = "Alice,25,New York,Engineer";
string[] fields = csvRow.Split(',');
foreach (string field in fields)
{
    Console.WriteLine(field);
}
// Alice / 25 / New York / Engineer

// Example using a string as the delimiter.
string sentence = "apple, banana, cherry";
string[] fruits = sentence.Split(", ");
Console.WriteLine(fruits[0]); // apple
Console.WriteLine(fruits.Length); // 3

// Use string.Join() to join an array.
string[] languages = { "C#", "Java", "Python" };
string joined = string.Join(" / ", languages);
Console.WriteLine(joined); // C# / Java / Python

// A common pattern: Split, process, then Join.
string tagString = "csharp,dotnet,programming";
string[] tags = tagString.Split(',');
string result = string.Join(" | ", tags);
Console.WriteLine(result); // csharp | dotnet | programming

Split() is an instance method (called on a string instance), while string.Join() is a static method (called on the string class itself). Keep this distinction in mind.

If delimiters appear consecutively (e.g., "a,,b"), empty elements are included in the resulting array. To exclude empty entries, use Split(',', StringSplitOptions.RemoveEmptyEntries).

For string padding and formatting, see PadLeft() / PadRight().