How to Convert Object to Comma Separated String in C#?

In this C# tutorial, I will explain to you with examples and practical code on how to convert object to comma separated string in C#.

Table of Contents

Convert Object to Comma Separated String in C#

There will be situations where you are required to convert an object or a list of objects into a comma-separated string in C#. So, let us find out various techniques to convert objects into comma-separated strings in C#.

You can use one of the below 4 methods to convert the object to a separated string in C#.

Using String.Join() method
Using Simple Object Conversion
Using LINQ to Transform a List of Objects
Using Custom Object Conversion

1. Using C# String.Join() method

C# provides a built-in method called String.Join , which is one of the most straightforward ways to create a comma-separated string from a collection. Here’s the simplest example:

using System;

namespace CommaSeparatedStringExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] fruits = { "Apple", "Banana", "Cherry" };
            string result = String.Join(",", fruits);
            Console.WriteLine(result);
        }
    }
}

Here, you can see I run the above code in a console application using Visual Studio, and you can see the output in the screenshot below.

convert object to comma separated string c#

2. Using Simple Object Conversion

Imagine you have a list of integers, and you want to convert this list into a comma-separated string in C#. Here’s how to do it with the complete code:

using System;
using System.Collections.Generic;

namespace IntegerListToCSV
{
    class Program
    {
        static void Main(string[] args)
        {
            List<int> numbers = new List<int>() { 1, 2, 3, 4, 5 };
            string result = String.Join(",", numbers);
            Console.WriteLine(result);
        }
    }
}

Now, when you run the above code, you can see the output in the screenshot below:

how to convert object to comma separated string c#

3. Using LINQ to Transform a List of Objects

Let’s say you have a list of custom objects and want to convert each object’s specific property to a comma-separated string. Here, you can use LINQ (Language Integrated Query).

Here’s an example with a class named Person with the complete code.

using System;
using System.Collections.Generic;
using System.Linq;

namespace LINQExample
{
    class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            List<Person> persons = new List<Person>()
            {
                new Person { Name = "John", Age = 25 },
                new Person { Name = "Jane", Age = 30 },
                new Person { Name = "Doe", Age = 22 }
            };

            string names = String.Join(",", persons.Select(p => p.Name));
            Console.WriteLine(names);  // Output: John,Jane,Doe
        }
    }
}

4. Using Custom Object Conversion

Sometimes, you may need to convert multiple properties of an object to a comma-separated string in C#. For instance, each object could be represented as “Name:Age” and then each object’s representation could be combined into a larger comma-separated string. Here’s how to achieve that with a complete example.

using System;
using System.Collections.Generic;
using System.Linq;

namespace CustomObjectToCSV
{
    class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            List<Person> persons = new List<Person>()
            {
                new Person { Name = "John", Age = 25 },
                new Person { Name = "Jane", Age = 30 },
                new Person { Name = "Doe", Age = 22 }
            };

            string result = String.Join(",", persons.Select(p => $"{p.Name}:{p.Age}"));
            Console.WriteLine(result);  // Output: John:25,Jane:30,Doe:22
        }
    }
}

Conclusion

Converting objects to comma-separated strings in C# is possible by using built-in methods like String.Join and powerful features like LINQ. I hope you understood “how to convert an object to comma-separated string c#.”