C# 0 The Complete Reference

r

, uses a 

for

loop, and has a 

return

 statement. These are legal inside a statement lambda. In essence, a 

statement lambda closely parallels an anonymous method. Therefore, many anonymous 

methods will be converted to statement lambdas when updating legacy code. (As mentioned, 

as of C# 3.0, lambda expressions are the preferred way of creating anonymous functions.) 

One other point: When a 

return

 statement occurs within a lambda expression, it simply 

causes a return from the lambda. It does not cause the enclosing method to return.

Before concluding, it is worthwhile to see another example that shows the statement 

lambda in action. The following program reworks the first delegate example in this chapter 

so it uses statement lambdas (rather than standalone methods) to accomplish various string 

modifications:

// The first delegate example rewritten to use

// statement lambdas.

using System;

// Declare a delegate type.

delegate string StrMod(string s);

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class UseStatementLambdas {

  static void Main() {

    // Create delegates that refer to lambda expressions

    // that perform various string modifications.

    // Replaces spaces with hyphens.

    StrMod ReplaceSpaces = s => {

             Console.WriteLine("Replacing spaces with hyphens.");

             return s.Replace(' ', '-');

           };

    // Remove spaces.

    StrMod RemoveSpaces = s => {

             string temp = "";

             int i;

             Console.WriteLine("Removing spaces.");

             for(i=0; i < s.Length; i++)

               if(s[i] != ' ') temp += s[i];

             return temp;

           };

    // Reverse a string.

    StrMod Reverse = s => {

             string temp = "";

             int i, j;

             Console.WriteLine("Reversing string.");

             for(j=0, i=s.Length-1; i >= 0; i--, j++)

             temp += s[i];

             return temp;

           };

    string str;

    // Call methods through the delegate.

    StrMod strOp = ReplaceSpaces;

    str = strOp("This is a test.");

    Console.WriteLine("Resulting string: " + str);

    Console.WriteLine();

    strOp = RemoveSpaces;

    str = strOp("This is a test.");

    Console.WriteLine("Resulting string: " + str);

    Console.WriteLine();

    strOp = Reverse;

    str = strOp("This is a test.");

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