String.Join Method (String, String[]) (System)

.NET Framework Class Library

String..::.Join Method (String, array<String>[]()[])

Concatenates a specified separator String between each element of a specified String array, yielding a single concatenated string.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

Syntax

Visual Basic (Declaration)

Public Shared Function Join ( _
    separator As String, _
    value As String() _
) As String

Visual Basic (Usage)

Dim separator As String
Dim value As String()
Dim returnValue As String

returnValue = String.Join(separator, _
    value)

public static string Join(
    string separator,
    string[] value
)

Visual C++

public:
static String^ Join(
    String^ separator, 
    array<String^>^ value
)

JScript

public static function Join(
    separator : String, 
    value : String[]
) : String

Parameters

separator: Type: System..::.String
A String.

value: Type: array<System..::.String>[]()[]
An array of String.

Return Value

Type: System..::.String
A String consisting of the elements of value interspersed with the separator string.

Exceptions

Exception	Condition
ArgumentNullException	value is nullNothingnullptra null reference (Nothing in Visual Basic).

Remarks

For example if separator is ", " and the elements of value are "apple", "orange", "grape", and "pear", Join(separator, value) returns "apple, orange, grape, pear".

If separator is nullNothingnullptra null reference (Nothing in Visual Basic), the empty string (Empty) is used instead.

Examples

The following example demonstrates the Join method.

Visual Basic

Imports System

Public Class JoinTest

    Public Shared Sub Main()

        Console.WriteLine(MakeLine(0, 5, ", "))
        Console.WriteLine(MakeLine(1, 6, "  "))
        Console.WriteLine(MakeLine(9, 9, ": "))
        Console.WriteLine(MakeLine(4, 7, "< "))
    End Sub 'Main


    Private Shared Function MakeLine(initVal As Integer, multVal As Integer, sep As String) As String
        Dim sArr(10) As String
        Dim i As Integer


        For i = initVal To (initVal + 10) - 1
            sArr((i - initVal)) = [String].Format("{0,-3}", i * multVal)

        Next i
        Return [String].Join(sep, sArr)
    End Function 'MakeLine
End Class 'JoinTest

using System;

public class JoinTest {
    public static void Main() {

        Console.WriteLine(MakeLine(0, 5, ", "));
        Console.WriteLine(MakeLine(1, 6, "  "));
        Console.WriteLine(MakeLine(9, 9, ": "));
        Console.WriteLine(MakeLine(4, 7, "< "));
    }

    private static string MakeLine(int initVal, int multVal, string sep) {

        string [] sArr = new string [10];

        for (int i = initVal; i < initVal + 10; i++)
            sArr[i - initVal] = String.Format("{0,-3}", i * multVal);

        return String.Join(sep, sArr);
    }
}

Visual C++

using namespace System;
String^ MakeLine( int initVal, int multVal, String^ sep )
{
   array<String^>^sArr = gcnew array<String^>(10);
   for ( int i = initVal; i < initVal + 10; i++ )
      sArr[ i - initVal ] = String::Format( "{0, -3}", i * multVal );
   return String::Join( sep, sArr );
}

int main()
{
   Console::WriteLine( MakeLine( 0, 5, ", " ) );
   Console::WriteLine( MakeLine( 1, 6, "  " ) );
   Console::WriteLine( MakeLine( 9, 9, ": " ) );
   Console::WriteLine( MakeLine( 4, 7, "< " ) );
}

JScript

import System;

public class JoinTest {
    public static function Main() : void {
        Console.WriteLine(MakeLine(0, 5, ", "));
        Console.WriteLine(MakeLine(1, 6, "  "));
        Console.WriteLine(MakeLine(9, 9, ": "));
        Console.WriteLine(MakeLine(4, 7, "< "));
    }

    private static function MakeLine(initVal : int, multVal : int, sep : String) : String  {

        var sArr : String [] = new String [10];

        for (var i : int = initVal; i < initVal + 10; i++)
            sArr[i - initVal] = String.Format("{0,-3}", i * multVal);

        return String.Join(sep, sArr);
    }
}
JoinTest.Main();

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

Reference