I think that if you are really learning youself Visual Basic, so you should be really try to figure out this?
One solution is to search each postion of a string to find if the string postion value is the same as letter “a” (in your case) and then just add the result into a counter.
Here’s a simple solution, which counts the occurances of “a” in TextBox1 and displays the result in TexbtBox2.
Note that this is a case-sensitive (and hard-coded) solution. This code only calculates the occurrances of letter “a” (not “A”). If you want to count both lower and upper case occurrances, you could try to think about that yourself.
Dim iCount As Integer
Dim iStringLen As Integer
Dim sString As String
iCount = 0
sString = Text1.Text ‘string given by user
For iPos = 1 To Len(sString)
‘ search each positition of the string
‘the Len() function calculates the length of the string.
‘ Comapre each postion with “a”
If Mid(sString, iPos, 1) = “a” Then
iCount = iCount + 1
‘ Display the result
Text2.Text = iCount