String Replace

Farooque Ali

14y2.6k.NET

Hi,Below is my program to replace the string A to Z, B to Y .. . ..... Z to A and so on

PrivateSub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim sample As String
sample = TextBox1.Text
Dim letter As String = "AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz"
Dim letter1 As String = "ZzYyXxWwVvUuTtSsRrQqPpOoNnMmLlKkJjIiHhGgFfEeDdCcBbAa"
For Each s As String In sample
Dim i As Integer
For i = 0 To letter.Length - 1
If s = letter(i) Then
TextBox2.Text += letter1(i)
End If
Next
Next

End Sub

Here i want the program, that should have only one for loop and inside the loop should not use the if conditions. Need the optimized code. Can anyone help me please

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
You can do it as long as a Select statement is permitted within the For Each statement. In fact, if you do this you can cope with non-letter characters as well by simply copying them, unchanged, to the second textbox:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim sample As String
sample = TextBox1.Text
TextBox2.Text = ""
Dim temp As String = ""
Dim i As Integer
Dim d As Char

For Each c As Char In sample

Select Case c
Case "A"c To "Z"c
i = AscW(c) - 64
d = ChrW(91 - i)
Case "a"c To "z"c
i = AscW(c) - 96
d = ChrW(123 - i)
Case Else
d = c
End Select

temp += d
Next

TextBox2.Text = temp

End Sub
Farooque Ali14y ago
Hi,

Thanks for your reply, But here one more thing need to be discussed, The string which is declared as letter and letter1 should not use that also,

Is any other way there to create program without using that declaration.
Vulpes14y ago
As long as TextBox1 is guaranteed not to contain any characters other than letters, then this should work.

However, if there are other characters, you'll get an exception and the only way to prevent that is to use an 'If' statement within the For Each loop.

Notice that it's best to build up the translated string within a temporary variable and then assign it to TextBox2.Text so you only have to alter the UI once:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim sample As String
sample = TextBox1.Text
TextBox2.Text = ""
Dim letter As String = "AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz"
Dim letter1 As String = "ZzYyXxWwVvUuTtSsRrQqPpOoNnMmLlKkJjIiHhGgFfEeDdCcBbAa"
Dim temp As String = ""

For Each c As Char In sample
Dim i As Integer = letter.IndexOf(c)
temp += letter1(i)
Next

TextBox2.Text = temp

End Sub