C# newbie questions

[sinha]

Hi!

I am a newbie on c#.

I have two simple questions:

a) How to print current date and time on my web page. Do I need to include any namespace for it.

b) How to check for null values. I create a dataset. For each item of the rows, I want to perform a nukk checking.

[MrPolite]

use DateTime.Now
you can call the .ToShortDateString(), the .ToLongDateString(), or the .ToString() method of that class. ToString would let you customize the way the date is formatted. If you use ToString then you can look up here on MSDN on the formatting strings you can use http://msdn.microsoft.com/library/en-us/cpguide/html/cpconstandarddatetimeformatstrings.asp?frame=true

I dunno about datasets, but in general if (item == null) // do something;

[jmcilhinney]

Although I've developed in C# I've only ever actually tried what you're asking in VB. I think the correct C# syntax is:

if (myDataRow["fieldname"].GetType() == typeof(DBNull))

or also:

if (myDataRow["fieldname"] == DBNull.Value)

[mar_zim]

or you can do a loop to your dataset

foreach(Datarow dr in mydataset.tables[0].rows){
if(dr[0].tostring=="")<---indicates 1st column
{
//do your job
}
}

[jmcilhinney]

or you can do a loop to your dataset

foreach(Datarow dr in mydataset.tables[0].rows){
if(dr[0].tostring=="")<---indicates 1st column
{
//do your job
}
}
What if the field contains an empty string? That's not a null value but will still return true in this case.

[mar_zim]

ouchh. sorry im asumming it won't contain empty string. coz usually if i check a null value i used "".

this one will work. if (myDataRow["fieldname"] == DBNull.Value)

[sinha]

Thanks a bunch ..........