Newbie For Loop Help

Hi, I'm taking a VB class in school, and I'm going nuts trying to figure something out.

Basically, I need to make a password verification app. It has to be at least 6 characters long, and contain 1 number, and 1 letter. I've been able to get the number check, and length check, but I can't get the letter check.

I thought what the best idea would be is to make a for loop to check for numbers, and if the amount of numbers equals the length of the string, then it would fail the check.

What I coded was this:

For i = 0 To 9
For j = 0 To 9
If txtPass.Text.IndexOf(i) = j Then
intLetterCheck = intLetterCheck + 1
End If
Next j
Next i

If txtPass.Text.Length = intLetterCheck Then
MessageBox.Show("The password must contain a letter!", "No letter.", MessageBoxButtons.OK, MessageBoxIcon.Error)
intLetterVerify = 1
End If

The problem is, that intLetterCheck always just shows the value of 1.

Any advice as to what I'm missing?

You're really overcomplicating this, and also inadvertently only checking the first 9 characters of the string for a number. This would make a password like "EnglandFranceGermany3" fail, even though it's valid, since IndexOf(3) would return 20. Since 20 > 9, it will never be equal to j.

There's a simpler way. The shared methods Char.IsLetter and Char.IsDigit will tell you if a given character is a letter or a digit. Due to a clever implementation by the .NET designers, you can treat a string as if it were an array of characters. With these two facts, you should be well on your way. Here's a hint, with ??? in places where you fill in the blanks.:

Dim foundDigit As Boolean = False
Dim foundLetter As Boolean = False

For i As Integer = 0 To txtPass.Text.Length - 1
If Char.IsDigit(txtPass.Text(i)) Then
???
End If

If ???(txtPass.Text(i)) Then
foundLetter = ???
End If
Next

Dim passwordValid as Boolean = ???

Thank you very much for your help.

My apologies for the long reply. Finals have me slammed, and I had to finish some things before my VB final.

Cheers!