Display characters Vertically in Listbox?

[Greenhorn]

Hey guys, new to the forum as of today and am looking forward to learning a lot from you all. Currently I'm working on a VB basic form for my college programming class. One of the requirements is to display the text in a list box in reverse order and vertically. I have this for the reversal of the text:

 

lstbxItemsPurchased.Items.Add(StrReverse(txtItemPurch.Text))

 

However, I have no idea how to make characters displayed vertically and seperately from each other in terms of the line they are one.

 

Here's a sample but I want this to work regardless of the number of characters entered.

 

"laptop computer" should become:

 

r

e

t

u

p

m

o

c

 

p

o

t

p

a

l

 

Thanks in advance guys

[orca44]

Welcome to the forum. :)

 

Since each letter should be displayed on a seperate line, there should be a .Add() call for each letter. So, you have to loop through the string from front to back, or back to front and add each letter to the listbox seperately.

[snarfblam]

It sounds to me like the purpose of this excersise is to learn and practice loops. To that end, StrReverse is not the correct approach. That would be like a student using a calculator on a long division test. If you're looking to do the reversing yourself, here are my thoughts.

 

You can get individual characters from a string using the Chars property. (Since Chars is the "default property", you could also just use parens.)

Dim SomeString As String = "ABCDEFG"

[color="Green"]' Get the third character of a string[/color]
MessageBox.Show(SomeString.Chars(2))
[color="Green"]' This is equivalent and produces identical results.[/color]
MessageBox.Show(SomeString(2))

 

You can reverse a string with a loop that goes from the last character to the first, taking each character and appending it to a variable. Remember that the character indecies start at zero, so the last character would be one less than the length of the string:

Dim LastIndex As Integer = SomeString.Length - 1

To run a loop backwards, you need to specify a negative step.

[color="Green"]' A value of -1 is added to i each iteration, until endValue is reached[/color]
For i As Integer = startValue To endValue [color="Blue"]Step - 1[/color]

And, just to cover all my bases, you use the & symbol to combine strings.

Dim ABCD As String = "ABCD"
Dim DCBA As String = ABCD(3) [color="Green"]'D'[/color]
DCBA = DCBA & ABCD(2) [color="Green"]'D' & 'C' -> 'DC'[/color]
DCBA = DCBA & ABCD(1) [color="Green"]'DC' & 'B' -> 'DCB'[/color]
DCBA = DCBA & ABCD(0) [color="Green"]'DCB' & 'A' -> 'DCBA'[/color]

That's everything you would need to reverse a string if StrReverse did not exist.