VB.NET Log Example – Code Sample Syntax

VB.NET Log Example – Code Sample Syntax

Purpose: – Illustrates using .

Purpose:
takes a double data type number and returns the natural
(base e) logarithm as a double data type.

Syntax:
Log(doublenumber)

Parameters Description
doublenumber Any valid System.Double data type number
1. Positive – returns natural logarithm
2. Zero – returns -Infinity
3. Negative – returns NaN (Not a Number)

Result Data Type Description
double the natural (base e) logarithm

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

Imports System.Math
Public Class clsLog
 
    Public Sub Main()
 
 
        '********************************************************************************
        ' Purpose: takes a double data type number and returns the natural
        ' (base e) logarithm as a double data type.
        ' 
        '
        ' Syntax: 	Log(doublenumber)
        '  
        ' Parameter1: doublenumber - Any valid System.Double data type number
        ' 1. Positive - returns natural logarithm
        ' 2. Zero - returns -Infinity
        ' 3. Negative - returns NaN (Not a Number)
        '
        ' Result: double - the natural (base e) logarithm
        '
        '********************************************************************************
        ' This example is from http://idealprogrammer.com
 
        Console.WriteLine("Example #1: 	Log(doublenumber)")
 
        Console.WriteLine(Log(90)) ' Returns 4.49980967033027
 
        'write blank line to make output easier to read
        Console.WriteLine()
 
        Console.WriteLine("Example #2: 	Log(doublenumber)")
 
        Console.WriteLine(Log(-3.4)) ' Returns NaN Not a Number
        'write blank line to make output easier to read
        Console.WriteLine()
 
        Console.WriteLine("Example #3: 	Log(doublenumber)")
 
 
 
        Console.WriteLine(Log(0)) ' Returns -Infinity
 
        '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 myclsLog As New clsLog
        myclsLog.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 Functions Log

  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 “Functions”
    • Right-click project name in solution explorer;
    • add new folder;
    • name of folder could be: Functions
  4. Add New subfolder named “MathFunctions”
    • Right-click Functions folder in solution explorer;
    • add new folder;
    • name of folder could be: MathFunctions
  5. Add Class Named clsLog to MathFunctions folder
    • Right-click MathFunctions folder;
    • add new item;
    • Select class
    • Class name could be clsLog
  6. Click on Visual Basic in code in step 1 above to copy code into clsLog.vb
  7. Click on Visual Basic in code in step 2 above to copy code into Module1.vb
  8. Click green arrow or press F5 to run program