C# 0 The Complete Reference

Splitting and Joining Strings

Two fundamental string-handling operations are split and join. A 

split

 decomposes a string 

into its constituent parts. A 

join

 constructs a string from a set of parts. To split a string, 

String

 defines 

Split( )

. To join a set of strings, 

String

 provides 

Join( )

.

There are several versions of 

Split( )

. Two commonly used forms, which have been 

available since C# 1.0, are shown here:

public string[ ] Split(params char[ ] 

seps

)

public string[ ] Split(params char[ ] 

seps

, int 

count

)

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The first form splits the invoking string into pieces and returns an array containing the 

substrings. The characters that delimit each substring are passed in 

seps.

 If 

seps

 is null or 

refers to an empty string, then whitespace is used as the separator. In the second form, no 

more than 

count

 substrings will be returned.

The two forms of the 

Join( )

 method are shown here:

public static string Join(string 

sep

, string[ ] 

strs

)

public static string Join(string 

sep

, string[ ] 

strs

, int 

start

, int 

count

)

The first form returns a string that contains the concatenation of the strings in 

strs.

 The 

second form returns a string that contains the concatenation of 

count

 strings in 

strs,

beginning at 

strs

[

start

]. For both versions, each string is separated from the next by the 

string specified by 

sep.

The following program demonstrates