[RESOLVED] How to add a value in same text box ?

[dunfiddlin]

Is the intention to add all the digits of the number whatever its size? So 23456 would be 16, for example? In that case you need to split the text into single digits.

Dim i As Integer = 0
        For Each digit In TextBox1.Text 'takes advantage of nature of string as char array
            i += Val(digit)
        Next
        TextBox2.Text = i.ToString