C# 0 The Complete Reference

object

 forms of 

Concat( )

 are 

very convenient because they let you avoid having to manually obtain string representations 

prior to concatenation. To see how useful these methods can be, consider the following 

program:

// Demonstrate the object form of Concat().

using System;

class MyClass {

  public static int Count = 0;

  public MyClass() { Count++; }

}

class ConcatDemo {

  static void Main() {

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    string result = String.Concat("The value is " + 19);

    Console.WriteLine("result: " + result);

    result = String.Concat("hello ", 88, " ", 20.0, " ",

                           false, " ",  23.45M);

    Console.WriteLine("result: " + result);

    MyClass mc = new MyClass();

    result = String.Concat(mc, " current count is ",

                           MyClass.Count);

    Console.WriteLine("result: " + result);

  }

}

The output is shown here:

result: The value is 19

result: hello 88 20 False 23.45

result: MyClass current count is 1

In this example, 

Concat( )

 concatenates the string representations of various types of 

data. For each argument, the 

ToString( )

 method associated with that argument is called to 

obtain a string representation. Thus, in this call to 

Concat( )

string result = String.Concat("The value is " + 19);