C# 4 and .NET 4

exception Handling ❘ OC175
printfn "%d" i
i++
if i > = 3
looping < - false
foreach statement
The foreach statement makes use of the interface IEnumerable . foreach doesn ’ t exist with ANSI C++ but
is an extension of ANSI C++/CLI. Unlike the C# foreach , in C++/CLI there ’ s a blank space between for
and each . F# uses this functionality for the for / in / do keywords:
// C#
int[] arr = {1, 2, 3};
foreach (int i in arr)
{
Console.WriteLine(i);
}
// C++/CLI
array < int > ^ arr = {1, 2, 3};
for each (int i in arr)
{
Console::WriteLine(i);
}
' Visual Basic
Dim arr() As Integer = New Integer() {1, 2, 3}
Dim num As Integer
For Each num as Integer In arr
Console.WriteLine(num)
Next
// F#
for i in arr do
printfn i
foreach makes it easy to iterate through a collection and C# supports creating
enumerations by using the yield statement. With Visual Basic and C++/CLI, the
yield statement is not available. Instead, it is necessary to implement the interfaces
IEnumerable and IEnumerator manually with these languages. The yield statement
is explained in Chapter 6.
eXCePTion handling
Exception handling is discussed in Chapter 15, “ Errors and Exceptions. ” This is extremely similar among
three languages. All these languages use try / catch / finally for handling exceptions, and the throw
keyword to create an exception. F# uses raise for throwing exceptions, and try / with / finally for
handling exceptions:
// C#
public void Method(Object o)
{
if (o == null)
throw new ArgumentException("Error");
}
public void Foo()
{
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