Optional parameter

[Curious]

I have two methods that are almost identical, except for the
"HtmlLogger varLogger" parameter passed to #2.
In #1, it uses a default HtmlLogger "logger" while in #2, it uses
"varLogger" parameter.

Other than that, the two methods are identical. I would like to
combine the two methods into a single method, but I wish to know:

- How to identify the optional parameter in the method; and
- When there is no optional parameter passed to the method, how to set
the default as "logger".

Method #1:

void PublishNegative Alpha ( IGridEntry entry)
{
try
{
foreach (NegativeAlphaF orEntry negA in mNegativeAList)
{

if (negA.List == entry.List.Name &&
negA.Ticker == entry.Ticker &&
negA.TargetShar es == entry.TargetSha res)
{

ESide side = entry.TargetSid e;
string strSide = GetSideString(s ide);

if (negA.Side == strSide)
{
NegativeAlpha neg = new NegativeAlpha() ;
neg.ObjectId = entry.ObjectId;
neg.NegativeSta tus = "Negative Alpha";

CustomObjectMan ager.Publish(ne g,
PublishMode.Reg ular);


logger.LogMessa geBarMessage(ES everity.Detail, "Published negative
alpha for ticker " + negA.Ticker);

break;
}
}
}
}
catch (Exception e)
{
logger.LogMessa geBarMessage(ES everity.Error,
e.Message);
}
}


Method #2:

void PublishNegative Alpha ( IGridEntry entry, HtmlLogger
varLogger)
{
try
{
foreach (NegativeAlphaF orEntry negA in mNegativeAList)
{

if (negA.List == entry.List.Name &&
negA.Ticker == entry.Ticker &&
negA.TargetShar es == entry.TargetSha res)
{

ESide side = entry.TargetSid e;
string strSide = GetSideString(s ide);

if (negA.Side == strSide)
{
NegativeAlpha neg = new NegativeAlpha() ;
neg.ObjectId = entry.ObjectId;
neg.NegativeSta tus = "Negative Alpha";

CustomObjectMan ager.Publish(ne g,
PublishMode.Reg ular);


varLogger.LogMe ssageBarMessage (ESeverity.Deta il, "Published negative
alpha for ticker " + negA.Ticker);

break;
}
}
}
}
catch (Exception e)
{
varLogger.LogMe ssageBarMessage (ESeverity.Erro r,
e.Message);
}
}

[Jon Skeet [C# MVP]]

Re: Optional parameter

Curious <fir5tsight@yah oo.comwrote:

I have two methods that are almost identical, except for the
"HtmlLogger varLogger" parameter passed to #2.
In #1, it uses a default HtmlLogger "logger" while in #2, it uses
"varLogger" parameter.
>
Other than that, the two methods are identical. I would like to
combine the two methods into a single method, but I wish to know:
>
- How to identify the optional parameter in the method; and
- When there is no optional parameter passed to the method, how to set
the default as "logger".

There's no such thing as an optional parameter in C#. The trick is to
make one overload call the other, supplying an appropriate default (in
this case "logger"). In other words, change PublishNegative Alpha(entry)
to:

void PublishNegative Alpha (IGridEntry entry)
{
PublishNegative Alpha(entry, logger);
}

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

[Curious]

Re: Optional parameter

Hi, Jon,

That's a great idea! Thanks.