C# || operator not working for masked textboxes

Question

I want to validate two masked textboxes. At least one of them needs to have a value. I have the following code

bool validatePhoneNumbers() 
{
     bool valid = false;
     if (!txtClientFax.MaskCompleted || !txtClientMobile.MaskCompleted) 
     {
          MessageBox.Show("Please enter telephone or mobile number under Client Section");
     }
     return valid;
}

If i test separately without using || it works. I want to check for both masked textboxes all at once

There is nothing special about this code, and it's not related to MaskedTextBoxes. You're just comparing booleans. Boolean logic is relatively simple. Write out _exactly_ what you want to happen and explain what "doesn't work". Also, please don't use Hungarian notation (`txt` prefix). — CodeCaster, Aug 31 '15 at 10:02
No, you don't. You want to check whether both textboxes _don't_ have a value. — CodeCaster, Aug 31 '15 at 10:06

score 1 · Accepted Answer · answered Aug 31 '15 at 10:06

Boolean logic is fundamental and simple. Prevent double negatives and write out your input. After that, you can simplify and reduce the expressions.

bool faxEntered = txtClientFax.MaskCompleted;
bool mobileEntered = txtClientMobile.MaskCompleted;

bool neitherEntered = !faxEntered && !mobileEntered;

if (neitherEntered)
{
    // show alert
}

Above if() checks whether both textboxes don't have a value entered. If either has one, the neitherEntered will be false.

You can reverse it:

bool eitherEntered = faxEntered || mobileEntered;

if (!eitherEntered)
{
    // show alert
}

score 0 · Answer 2 · answered Aug 31 '15 at 09:57

0

bool validatePhoneNumbers() 
{
 bool valid = false;
 if (!(txtClientFax.MaskCompleted || txtClientMobile.MaskCompleted))
 {
      MessageBox.Show("Please enter telephone or mobile number under Client Section");
 }
 return valid;
}

answered Aug 31 '15 at 09:57

andy

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C# || operator not working for masked textboxes

2 Answers2