String.Concat Method (Object, Object)

Updated: October 2010

Concatenates the string representations of two specified objects.

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

public static string Concat(
	Object arg0,
	Object arg1


Type: System.Object
The first object to concatenate.
Type: System.Object
The second object to concatenate.

Return Value

Type: System.String
The concatenated string representations of the values of arg0 and arg1.

The method concatenates arg0 and arg1 by calling the parameterless ToString method of arg0 and arg1; it does not add any delimiters.

String.Empty is used in place of any null argument.

If either of the arguments is an array reference, the method concatenates a string representing that array, instead of its members (for example, "System.String[]").

The following code example demonstrates the Concat method.

using System;

class Example
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
      int i = -123;
      Object o = i;
      Object[] objs = new Object[] { -123, -456, -789 };

      outputBlock.Text += String.Format("Concatenate 1, 2, and 3 objects:") + "\n";
      outputBlock.Text += String.Format("1) {0}", String.Concat(o)) + "\n";
      outputBlock.Text += String.Format("2) {0}", String.Concat(o, o)) + "\n";
      outputBlock.Text += String.Format("3) {0}", String.Concat(o, o, o)) + "\n";

      outputBlock.Text += "\nConcatenate 4 objects and a variable length parameter list:" + "\n";
      outputBlock.Text += String.Format("4) {0}", String.Concat(o, o, o, o, o)) + "\n";

      outputBlock.Text += "\nConcatenate a 3 element object array:" + "\n";
      outputBlock.Text += String.Format("5) {0}", String.Concat(objs)) + "\n";
This example produces the following output:
Concatenate 1, 2, and 3 objects:
1) -123
2) -123-123
3) -123-123-123

Concatenate 4 objects and a variable length parameter list:
4) -123-123-123-123-123

Concatenate a 3 element object array:
5) -123-456-789


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.




October 2010

Revised the Remarks section.

Customer feedback.