VB.NET Filter() – Code Sample Syntax Example

VB.NET Filter Example – Code Sample Syntax

Abstract: – Illustrates using .

 *** 1. Download Source Code *** 

VB.NET Syntax StringManipulation Filter download Download Source Code for All VB Console Examples in One Project

 *** 2. Filter Syntax *** 


Purpose:
Returns a zero-based array containing a subset of a String array based on
specified filter criteria.


Syntax:
Filter (Source As String(), Match As String, Include As Boolean, _
Compare As CompareMethod) As String()

Parameters Description
Source Required – one-dimensional string array to be searched
Match required – string to search for
Include optional – Boolean value indicating whether to return substrings that
include or exclude Match.
Compare optional – numeric value indicating compare method – CompareMethod.Binary
or CompareMethod.Text

Result Data Type Description
array Returns a zero-based array containing a subset of a String array based on
specified filter criteria.


 *** 3. Filter – Quick Example *** 

Dim myStrings(3) As String
myStrings(0) = “This”
myStrings(1) = “is”
myStrings(2) = “my”
myStrings(3) = “string”
Dim FilteredStrings() As String
FilteredStrings = Filter(myStrings, “is”, True, CompareMethod.Text)
For Each myItem As String In FilteredStrings
Console.WriteLine(myItem) ‘ Returns [“This”, “Is”].
Next

 *** 4. Filter – Full Example *** 

Filter Example Output Screenshot


VB.NET Syntax StringManipulation Filter screenshot


Step 1: Click Visual Basic to Cut-n-paste code into clsFilter.vb

Option Compare Text
Public Class clsFilter
 
    Public Sub Main()
 
 
        '****************************************************************************************
        ' Purpose: Returns a zero-based array containing a subset of a String array based on
        ' specified filter criteria.
        '
        ' Syntax: 	Filter (Source As String(), Match As String, Include As Boolean, _
        ' Compare As CompareMethod) As String()
        '
        ' Parameter1: Source - Required - one-dimensional string array to be searched 
        '
        ' Parameter2: Match - required - string to search for
        '
        ' Parameter3: Include - optional - Boolean value indicating whether to return substrings that 
        ' include or exclude Match.
        '
        ' Parameter4: Compare - optional - numeric value indicating compare method - CompareMethod.Binary
        ' or CompareMethod.Text
        '
        ' Result: array - Returns a zero-based array containing a subset of a String array based on
        ' specified filter criteria.
        '
        ' Quick Example:  Dim myStrings(3) As String
        ' myStrings(0) = "This"
        ' myStrings(1) = "is"
        ' myStrings(2) = "my"
        ' myStrings(3) = "string"
        ' Dim FilteredStrings() As String
        ' FilteredStrings = Filter(myStrings, "is", True, CompareMethod.Text)
        ' For Each myItem As String In FilteredStrings
        '    Console.WriteLine(myItem) ' Returns ["This", "Is"].
        ' Next
        '
        ' *********************************************************
        ' Source - Required - one-dimensional string array to be searched
        ' Match - required - string to search for
        ' Include - optional - Boolean value indicating whether to return substrings that 
        ' include or exclude Match.
        ' Compare - optional - numeric value indicating compare method - CompareMethod.Binary
        ' or CompareMethod.Text
        '****************************************************************************************
 
        Console.WriteLine("Example #1: 	Filter(Source, Match, Include,Compare) As String")
        Dim myStrings(3) As String
        myStrings(0) = "This"
        myStrings(1) = "is"
        myStrings(2) = "my"
        myStrings(3) = "string"
 
        Dim FilteredStrings() As String
        FilteredStrings = Filter(myStrings, "is", True, CompareMethod.Text)
 
        For Each myItem As String In FilteredStrings
            Console.WriteLine(myItem) ' Returns ["This", "Is"].
        Next
 
 
 
        'write blank line to make output easier to read
        Console.WriteLine()
 
 
 
        'Prevent console from closing before you press enter
        Console.ReadLine()
 
    End Sub
 
 
End Class

Step 2: Click Visual Basic to Cut-n-paste code into Module1.vb

Module Module1
 
    Sub Main()
 
 
        Dim myclsFilter As New clsFilter
        myclsFilter.Main()
 
 
 
    End Sub
 
End Module

Prerequistes:

  1. Install Visual Basic (Express or Standard Edition)
  2. Install SQL Server Express
  3. Download Northwind and pubs Database
  4. Attach Northwind Database to Databases in Sql Express
  5. Attach pubs Database to Databases in Sql Express

Notes:

  • Console Application is used to simplify things, but Windows Forms or Web Forms could also be used
  • You can build a library of syntax examples by using same project over and over and just commenting out what you do not want to execute in Module1.vb

Instructions:
VB.NET Syntax StringManipulation Filter

  1. Use Visual Basic 2010 Express or Standard Edition
  2. Create new project;
    • Click File/New Project
    • Select Console Application Template
    • Select Visual Basic for Language
    • name of project could be VBNET_Syntax.
  3. Add New folder named “StringManipulation”
    • Right-click project name in solution explorer;
    • add new folder;
    • name of folder could be: StringManipulation
  4. Add Class Named clsFilter to StringManipulation folder
    • Right-click StringManipulation folder;
    • add new item;
    • Select class
    • Class name could be clsFilter
  5. Click on Visual Basic in code in step 1 above to copy code into clsFilter.vb
  6. Click on Visual Basic in code in step 2 above to copy code into Module1.vb
  7. Click green arrow or press F5 to run program