VB.NET中的Val（）函数如何工作？

Question

I have an assignment in VB.NET that I'm stuck with at the moment. Would love some help.

The question is this: You enter random characters into a textbox, for example 12ab3c4d5efgh, and at the click of a button, it must sort the characters in the textbox into 2 separate Labels, depending on whether or not the 'character' is a number or letter. So, continuing the example, Label1 must show '12345' and Label 2 must show 'abcdefgh'. I hope I made myself clear enough.

I was asked to use the Val() function but I really have no clue. Could someone please help? :D

Answer 1

This creates one string with the digits and one with the letters. Characters that are not digits or letters are ignored.

Dim chars As String = "12ab3c4d5efgh"
Dim nums As String = chars.Where(Function(c) Char.IsDigit(c)).ToArray 
Dim lets As String = chars.Where(Function(c) Char.IsLetter(c)).ToArray 

Answer 2

If you have to use Val() something like this would do. But be careful: Val("0") also returns 0 .

Dim numbers As String = String.Empty
Dim letters As String = String.Empty
Dim sourceString As String = "12ab3c4d50efgh"

For Each c As Char In sourceString
    If Val(c) = 0 And c <> "0" Then letters &= c Else numbers &= c
Next

Console.WriteLine("Numbers: " & numbers)
Console.WriteLine("Letters: " & letters)
Console.ReadKey()