C# class declaration

[hharry]

Hello All,

I came across this class declaration and don't really understand the
syntax
public sealed class PdfReport<ReportClass: PdfFormatter where
ReportClass : Root.Reports.Report, new()
{

}

Specifically the PdfReport<ReportClasspart.
Pointers appreciated

thanks in advance

[Jon Skeet [C# MVP]]

On Aug 19, 5:42*pm, hharry <[e-mail]:

I came across this class declaration and don't really understand the
syntax
public sealed class PdfReport<ReportClass: PdfFormatter where
ReportClass : Root.Reports.Report, new()
{

}

Specifically the PdfReport<ReportClasspart.
Pointers appreciated

It means that the type is generic. Generics is a big topic - too big
to do justice to in a newsgroup post - but there's plenty written
about it on the web. This MSDN article has several more linking off
it:
http://msdn.microsoft.com/en-us/library/512aeb7t.aspx

Jon

[hharry]

On Aug 19, 12:45*pm, "Jon Skeet [C# MVP]" <[e-mail]:

On Aug 19, 5:42*pm, hharry <[e-mail]:

I came across this class declaration and don't really understand the
syntax
public sealed class PdfReport<ReportClass: PdfFormatter where
ReportClass : Root.Reports.Report, new()
{

}

Specifically the PdfReport<ReportClasspart.
Pointers appreciated

It means that the type is generic. Generics is a big topic - too big
to do justice to in a newsgroup post - but there's plenty written
about it on the web. This MSDN article has several more linking off
it:http://msdn.microsoft.com/en-us/library/512aeb7t.aspx

Jon

Thanks Jon. I'll read-up on it.

[Peter Morris]

>public sealed class PdfReport<ReportClass: PdfFormatter where

>ReportClass : Root.Reports.Report, new()

>It means that the type is generic.

What is the ", new()" part? I don't recognise that.

[Jon Skeet [C# MVP]]

Peter Morris <mr*********@SPAMgmail.comwrote:

public sealed class PdfReport<ReportClass: PdfFormatter where
ReportClass : Root.Reports.Report, new()

It means that the type is generic.

What is the ", new()" part? I don't recognise that.

It's part of the generic type constraint - it means that the type
argument has to have a parameterless constructor. Within the class,
they could then do:

ReportClass x = new ReportClass();

You can't specify any parameterised constructors - just the
parameterless one.

--
Jon Skeet - <sk***@pobox.com>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon.skeet
C# in Depth: http://csharpindepth.com