Check string is null or empty in linq

Question

I have string with empty space("________")

string MyNote= Convert.ToString(Session["MyNote"]);

if(MyNote!=null || MyNote != "")
{


}

MyNote != "" does not work if string has more space so

How can I check my string is "" or null by using linq in C#?

If you really wanted to use LINQ the correct answer would have been if (MyNote != null && MyNote.Any(c => !char.IsWhitespace(c))) .... But I doubt this is about LINQ. — pescolino
– pescolino, Commented Oct 14, 2013 at 1:01

Jeroen Vannevel · Accepted Answer · 2013-10-14 01:09:21Z

5

String.IsNullOrWhiteSpace is the method you're looking for.

Indicates whether a specified string is null, empty, or consists only of white-space characters.

Alternatively, using your idea:

if(MyNote!=null && MyNote.Trim() != "")
{

}

or

if(MyNote!=null && MyNote.Trim().Length == 0)
{

}

answered Oct 13, 2013 at 11:11

Jeroen Vannevel

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1 Comment

You should change || into &&. You actually check for Is Not Null Or Not WhiteSpace. This will even throw an exception if MyNote is null.

zkanoca · Accepted Answer · 2013-10-13 11:09:07Z

2

if(MyNote!=null || MyNote.Length > 0) //or you may want to set different value than 0
{


}

answered Oct 13, 2013 at 11:09

zkanoca

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And with trimming it won't work either since it throws an exception when MyNote is null.

jade290 · Accepted Answer · 2015-05-08 13:51:36Z

0

This works for me:

 string MyNote = Session["MyNote"] == null ? String.Empty : Session["MyNote"].ToString();

answered May 8, 2015 at 13:51

jade290

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