Visual Basic 6.0

1. Click File >> New Project. You might be asked to save changes to the current project if you’ve been experimenting. If so, click the No button. If you want to keep your work, click Yes. Select Standard EXE from the New Project Window

2. Select the Form and change its property Name to frmSearch  and Caption to Search Box.

3. Insert 2 Text Box, 2 Labels, a Command Button and a Check Box on the form. Arrange the form as shown in figure.

4. Set Name Property as

Bigger Text Box Name – txtInput

Smaller Text Box Name – txtSearch

Command Button Name – cmdSearch

Check Box Name – chkCase

Set MultiLine property of txtINput to True.

5. Double-Click the Command Button to open code window and insert the following code.

   1:  Private Sub cmdSearch_Click()

   2:  Dim searchStringLength, inputLength, index As Integer, str, searchString As String

   3:  searchString = Trim(txtSearch.Text) 'Trim Leading and Trailing Spaces

   4:  inputLength = Len(txtInput.Text) 'Length of the Input

   5:  searchStringLength = Len(searchString) 'Length of the Search String

   6:  index = inputLength - searchStringLength + 1

   7:  For i = 1 To index Step 1

   8:      str = Mid(txtInput.Text, i, searchStringLength) 'Extract String of

   9:      If chkCase Then 'If Check Box is Checked

  10:       If StrComp(searchString, str, vbBinaryCompare) = 0 Then'Case Sensitive Search

  11:          Counter = Counter + 1

  12:       End If

  13:      Else

  14:       If StrComp(searchString, str, vbTextCompare) = 0 Then

  15:          Counter = Counter + 1

  16:       End If

  17:      End If

  18:  Next i

  19:   

  20:  If Counter <> 0 Then 

  21:      MsgBox "The String " & searchString & " is found " & Counter & " times.", 
                  vbOKOnly, "Result"

  22:      Counter = 0 

  23:  Else

  24:      MsgBox "No string found", vbOKOnly, "Result"

  25:  End If

  26:  End Sub

Variable searchStringLength stores the length of the string to be searched, variable inputLength stores the length of the input string and the line index = inputLength - searchStringLength + 1 sets the value of the variable index .

For example if the input string is “Learning Visual Basic is Interesting”  (without quotes) and search string is basic then,

inputLength = 36

searchStringLength = 5

index = 36 – 5 + 1 = 32

The value of txtSearch Text Box is stored in a string variable searchString by removing leading and trailing spaces using function Trim.

The variable chkCase used in line 9 is the name of the Check Box used in form.  So if the check box is checked then a Case Sensitive search is performed else case insensitive search is performed. The Attributes vbBinaryCompare and vbTextCompare in function strComp is for Case Sensitive and Case Insensitive search respectively.

The For loop goes from 1 to index i.e upto character s of word interesting, extracts 5 (searchStringLength) characters at a time using function Mid() and compares it with a search string (Basic in this example). If a match is found then the variable counter is increased by one. The result is displayed in a Message Box later.

Run the program by pressing F5 from the keyboard. Enter Input String, Search String and click Search Button.

6. Check Check Box for Case Sensitive search.

For String Handling Funtions Click Here