C# .Join()

The .Join() method concatenates an array or a collection of strings into a single string, with a specified separator inserted between each element.

This method is particularly useful for formatting lists, such as comma-separated values or readable sentences.

Syntax

string.Join(string separator, IEnumerable<string> values)

• separator: A string to insert between each element. If empty, elements are joined with no separator.
• values: An array or collection of strings to concatenate. null values in the collection are replaced with empty strings.

Example

This example demonstrates how .Join() uses a comma and space (,) as the separator to create a formatted to-do list.

using System;

class Program
{
    static void Main()
    {
        string[] studyTasks = { "Complete C# lesson", "Review notes", "Practice coding exercises", "Read documentation" };

        // Using .Join() to create a sequential to-do list with ", " as the separator
        string toDoList = string.Join(", ", studyTasks);

        Console.WriteLine("Today's Codecademy study plan: " + toDoList);
    }
}

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This example results in the following output:

Today's Codecademy study plan: Complete C# lesson, Review notes, Practice coding exercises, Read documentation

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Codebyte Example

The following example demonstrates how .Join() combines a collection of course names using an ampersand (&) to produce a readable list.

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