Best way to check that at least one textbox of many has content?

Question

I have a 'search page' where it is required that at least one textbox has some input. The following method verifies this like so:

    if (!String.IsNullOrEmpty(txtNome.Text))
    {
        return true;
    }
    if (!String.IsNullOrEmpty(txtEndereco.Text))
    {
        return true;
    }
    if (!String.IsNullOrEmpty(txtCidade.Text))
    {
        return true;
    }
    if (!String.IsNullOrEmpty(txtCEP.Text))
    {
        return true;
    }

    return false;

There hasn't been any problems with the results from this method. My question is related to performance: Is there a better way to make this check? One possible alternative I've thought of:

string X = String.Concat(txtNome.Text,...,txtCEP.Text)
if(!String.IsNullOrEmpty(X))
{
    return true;
} 

I think that using the if-return pattern is better when the first field isn't empty, but for other use-cases, using String.Concat is better.

Could someone let me know which way is better and why? Is there another, even better way?

Answer 1

If all the controls are of the same type, you could put all the controls you want to check in an array then use Linq's Any extension method:

return new[] { txtNome, txtEndereco, txtCidade, txtCEP }
    .Any(x => !String.IsNullOrEmpty(x.Text));

Or alternatively, if not all of the controls are of the same type, create an array of strings:

return new[] { txtNome.Text, txtEndereco.Text, txtCidade.Text, txtCEP.Text }
    .Any(x => !String.IsNullOrEmpty(x));

The performance difference between this and a plain old if-else-block will be negligible.