C# 0 The Complete Reference

Concatenating Strings

There are two ways to concatenate (join together) two or more strings. First, you can use 

the

+

 operator, as demonstrated in Chapter 7. Second, you can use one of the various 

concatenation methods defined by 

String

. Although using 

+

 is the easiest approach in 

many cases, the concatenation methods give you an alternative.

The method that performs concatenation is called 

Concat( )

. One of its most commonly 

used forms is shown here:

public static string Concat(string 

str1

, string 

str2

)

This method returns a string that contains 

str2

 concatenated to the end of 

str1.

 Another form 

of

Concat( )

, shown here, concatenates three strings:

public static string Concat(string 

str1

, string 

str2

, string 

str3

)

In this version, a string that contains the concatenation of 

str1, str2,

 and 

str3

 is returned. 

There is also a form that concatenates four strings:

public static string Concat(string 

str1

, string 

str2

, string 

str3

, string 

str4

)

This version returns the concatenation of all four strings.

The version of 

Concat( )

 shown next concatenates an arbitrary number of strings:

public static string Concat(params string[ ] 

strs

)

Here, 

strs

 refers to a variable number of arguments that are concatenated, and the result is 

returned. Because this version of 

Concat( ) 

can be used to concatenate any number of strings, 

including two, three, or four strings, you might wonder why the other forms just shown 

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