c# - How to convert a string array to a comma separated string

Convert a String Array to a comma-separated String
The Array class provides methods for creating, manipulating, searching, and sorting arrays. The Array class is not part of the System.Collections namespaces. However, it is still considered a collection because it is based on the IList interface. An element is a value in an Array. The length of an Array is the total number of elements it can contain. The Array has a fixed capacity.

The following .net c# tutorial code demonstrates how we can convert a String Array instance to a comma-separated String object. That means we will get a String instance from the elements of a String Array where the String instance contains the Array elements separated by comma delimiter. Here we will join the String Array elements with the comma separator and build an instance of the String object. In this .net c# example code, we will use the String class Join() method.

The String Join(String, String[]) method overload concatenates all the elements of a String array, using the specified separator between each element. The Join (string? separator, params string?[] value) method overload has two parameters those are separator and value. Here the separator parameter is the String to use as a separator and the value parameter is an Array that contains the elements to concatenate.

So, using this method overload we can join String Array elements to get a comma-separated String object. Here we will pass a comma for the separator parameter and the String Array for the value parameter. The String(separator, value) method returns a String that consists of the elements in value delimited by the separator String or an empty String if provided String Array contains zero elements.

The String Join(string? separator, params string?[] value) method overload throws ArgumentNullException if the value is null. It also throws OutOfMemoryException if the length of the resulting String overflows the maximum allowed length (Int32.MaxValue).

So finally, using this String class Join(String, String[]) method overload the .net c# developers can convert a String Array to a comma-separated String object.
convert-string-array-to-comma-separated-string.aspx

<%@ Page Language="C#" AutoEventWireup="true"%>    
    
<!DOCTYPE html>    
<script runat="server">  
    protected void Button1_Click(object sender, System.EventArgs e)    
    {  
        string[] birds = new string[]  
        {  
            "Horned Screamer",  
            "Cackling Goose",  
            "Greylag Goose",  
            "Andean Flamingo"
        };  
  
        Label1.Text = "birds array.........<br />";
        foreach (string s in birds)  
        {  
            Label1.Text += s + "<br />";  
        }

        string commaseparatedstring = String.Join(",", birds);
        Label1.Text += "<br />string array to comma separated string........<br />";
        Label1.Text += commaseparatedstring;
    }    
</script>    
    
<html xmlns="http://www.w3.org/1999/xhtml">    
<head id="Head1" runat="server">    
    <title>c# example - string array to comma separated string</title>    
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<body>    
    <form id="form1" runat="server">    
    <div>    
        <h2 style="color:DarkBlue; font-style:italic;">    
            c# example - string array to comma separated string
        </h2>    
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            ID="Label1"     
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            Font-Size="Large"    
            >    
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        <br /><br />  
        <asp:Button     
            ID="Button1"     
            runat="server"     
            Text="convert string array to comma separated string"    
            OnClick="Button1_Click"  
            Height="40"    
            Font-Bold="true"    
            />    
    </div>    
    </form>    
</body>    
</html>
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