How to enter textbox value if another textbox has value

If coding in .NET2, maybe you should be thinking about doing it in the Form Load() event, something like

If not string.isempty(TextBox1.Text) then
  if TextBox1.text = "11/02/2007" then
       Textbox2.text = "Finish"
  end if
end if

You can skip the test for empty string, Textbox1.Text will always return string

IF TextBox1.text = "11/02/2007" then Textbox2.text = "Finish"

The best events to hook it is possibly Textbox1.Validate or Exit (or even Change if you need to update as soon as they hit the last "7")

Dim date1 as DateTime 
		Dim date1OK as 	bool 
			date1 = new DateTime(1,1,1)
			
			try
			{
				date1 = Convert.ToDateTime(Date1.Text);
				Textbox2.text = "Finish"
			}
			catch
			{
				date1OK = false;
			}

Select allOpen in new window

>>You can skip the test for empty string, Textbox1.Text will always return string

true, but its considered best practice to perform all checks. plus once you get used to it it becomes sort of "instinctual"...

Um... it's a bit overkill isn't it.

String.IsEmpty(TextBox.Text)   ===   (True)

It's like adding

If TRUE then
  IF TRUE then
     IF TRUE then
        do something....

kinda moot point?

maybe so, but i like to think about it like algebra in high school: everybody thinks its useless, you'll never use it. maybe so, but it helps create the necessary neuronal connections for logical thinking (and later in life you one uses those skills in programming .net for example).

furthermore i would tend to think that checking for String.IsEmpty beforehand saves some computing power in doing the comparison IF TextBox1.text = "11/02/2007", which is pointless to run unless the textbox has something in it. i believe that the method IsEmpty is more efficient than the method to extract the Text property of the control when that text exists. i cant back that up, maybe somebody can comment on this?

imitchie, having googled a little bit i found some interesting factoids... apparently, the question about efficiency of checking for emptyness is addressed in this article:
http://www.tbiro.com/Check-empty-string-performance.htm

the conclusions from that one and others, apparently, is:
1) checking for String.Length() is faster than checking for String.IsEmpty()
2) checking for String.Length() is faster when length is shorter

meaning that a more efficient code would look maybe like this:

If String.Length > 0 Then
  If TextBox1.Text = "11/02/2007" Then
       Textbox2.Text = "Finish"
  End If
End If

What is your opinion on this?

vadim63,

Excellent snippet - very versatile.

I did test all the code samples but vadim63's was the only one that worked for me.

Thanks for all the responses.

Dave

Good luck!