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282 lines
12 KiB
Markdown
282 lines
12 KiB
Markdown
---
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language: Visual Basic
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contributors:
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- ["Brian Martin", "http://brianmartin.biz"]
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filename: learnvisualbasic.vb
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---
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```vb
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Module Module1
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Sub Main()
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' A Quick Overview of Visual Basic Console Applications before we dive
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' in to the deep end.
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' Apostrophe starts comments.
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' To Navigate this tutorial within the Visual Basic Complier, I've put
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' together a navigation system.
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' This navigation system is explained however as we go deeper into this
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' tutorial, you'll understand what it all means.
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Console.Title = ("Learn X in Y Minutes")
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Console.WriteLine("NAVIGATION") 'Display
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Console.WriteLine("")
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Console.ForegroundColor = ConsoleColor.Green
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Console.WriteLine("1. Hello World Output")
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Console.WriteLine("2. Hello World Input")
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Console.WriteLine("3. Calculating Whole Numbers")
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Console.WriteLine("4. Calculating Decimal Numbers")
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Console.WriteLine("5. Working Calculator")
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Console.WriteLine("6. Using Do While Loops")
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Console.WriteLine("7. Using For While Loops")
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Console.WriteLine("8. Conditional Statements")
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Console.WriteLine("9. Select A Drink")
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Console.WriteLine("50. About")
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Console.WriteLine("Please Choose A Number From The Above List")
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Dim selection As String = Console.ReadLine
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Select Case selection
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Case "1" 'HelloWorld Output
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Console.Clear() 'Clears the application and opens the private sub
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HelloWorldOutput() 'Name Private Sub, Opens Private Sub
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Case "2" 'Hello Input
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Console.Clear()
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HelloWorldInput()
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Case "3" 'Calculating Whole Numbers
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Console.Clear()
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CalculatingWholeNumbers()
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Case "4" 'Calculting Decimal Numbers
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Console.Clear()
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CalculatingDecimalNumbers()
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Case "5" 'Working Calcculator
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Console.Clear()
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WorkingCalculator()
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Case "6" 'Using Do While Loops
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Console.Clear()
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UsingDoWhileLoops()
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Case "7" 'Using For While Loops
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Console.Clear()
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UsingForLoops()
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Case "8" 'Conditional Statements
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Console.Clear()
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ConditionalStatement()
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Case "9" 'If/Else Statement
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Console.Clear()
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IfElseStatement() 'Select a drink
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Case "50" 'About msg box
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Console.Clear()
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Console.Title = ("Learn X in Y Minutes :: About")
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MsgBox("This tutorial is by Brian Martin (@BrianMartinn")
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Console.Clear()
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Main()
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Console.ReadLine()
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End Select
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End Sub
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'One - I'm using numbers to help with the above navigation when I come back
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'later to build it.
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'We use private subs to seperate different sections of the program.
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Private Sub HelloWorldOutput()
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'Title of Console Application
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Console.Title = "Hello World Ouput | Learn X in Y Minutes"
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'Use Console.Write("") or Console.WriteLine("") to print outputs.
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'Followed by Console.Read() alternatively Console.Readline()
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'Console.ReadLine() prints the output to the console.
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Console.WriteLine("Hello World")
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Console.ReadLine()
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End Sub
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'Two
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Private Sub HelloWorldInput()
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Console.Title = "Hello World YourName | Learn X in Y Minutes"
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' Variables
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' Data entered by a user needs to be stored.
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' Variables also start with a Dim and end with an As VariableType.
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' In this tutorial, we want to know what your name, and make the program
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' respond to what is said.
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Dim username As String
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'We use string as string is a text based variable.
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Console.WriteLine("Hello, What is your name? ") 'Ask the user their name.
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username = Console.ReadLine() 'Stores the users name.
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Console.WriteLine("Hello " + username) 'Output is Hello 'Their name'
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Console.ReadLine() 'Outsputs the above.
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'The above will ask you a question followed by printing your answer.
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'Other variables include Integer and we use Integer for whole numbers.
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End Sub
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'Three
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Private Sub CalculatingWholeNumbers()
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Console.Title = "Calculating Whole Numbers | Learn X in Y Minutes"
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Console.Write("First number: ") 'Enter a whole number, 1, 2, 50, 104 ect
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Dim a As Integer = Console.ReadLine()
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Console.Write("Second number: ") 'Enter second whole number.
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Dim b As Integer = Console.ReadLine()
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Dim c As Integer = a + b
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Console.WriteLine(c)
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Console.ReadLine()
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'The above is a simple calculator
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End Sub
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'Four
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Private Sub CalculatingDecimalNumbers()
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Console.Title = "Calculating with Double | Learn X in Y Minutes"
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'Of course we would like to be able to add up decimals.
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'Therefore we could change the above from Integer to Double.
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'Enter a whole number, 1.2, 2.4, 50.1, 104.9 ect
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Console.Write("First number: ")
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Dim a As Double = Console.ReadLine
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Console.Write("Second number: ") 'Enter second whole number.
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Dim b As Double = Console.ReadLine
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Dim c As Double = a + b
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Console.WriteLine(c)
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Console.ReadLine()
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'Therefore the above program can add up 1.1 - 2.2
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End Sub
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'Five
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Private Sub WorkingCalculator()
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Console.Title = "The Working Calculator| Learn X in Y Minutes"
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'However if you'd like the calculator to subtract, divide, multiple and
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'add up.
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'Copy and paste the above again.
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Console.Write("First number: ")
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Dim a As Double = Console.ReadLine
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Console.Write("Second number: ") 'Enter second whole number.
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Dim b As Integer = Console.ReadLine
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Dim c As Integer = a + b
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Dim d As Integer = a * b
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Dim e As Integer = a - b
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Dim f As Integer = a / b
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'By adding the below lines we are able to calculate the subtract,
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'multply as well as divide the a and b values
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Console.Write(a.ToString() + " + " + b.ToString())
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'We want to pad the answers to the left by 3 spaces.
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Console.WriteLine(" = " + c.ToString.PadLeft(3))
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Console.Write(a.ToString() + " * " + b.ToString())
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Console.WriteLine(" = " + d.ToString.PadLeft(3))
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Console.Write(a.ToString() + " - " + b.ToString())
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Console.WriteLine(" = " + e.ToString.PadLeft(3))
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Console.Write(a.ToString() + " / " + b.ToString())
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Console.WriteLine(" = " + e.ToString.PadLeft(3))
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Console.ReadLine()
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End Sub
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'Six
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Private Sub UsingDoWhileLoops()
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'Just as the previous private sub
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'This Time We Ask If The User Wishes To Continue (Yes or No?)
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'We're using Do While Loop as we're unsure if the user wants to use the
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'program more than once.
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Console.Title = "UsingDoWhileLoops | Learn X in Y Minutes"
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Dim answer As String 'We use the variable "String" as the answer is text
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Do 'We start the program with
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Console.Write("First number: ")
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Dim a As Double = Console.ReadLine
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Console.Write("Second number: ")
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Dim b As Integer = Console.ReadLine
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Dim c As Integer = a + b
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Dim d As Integer = a * b
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Dim e As Integer = a - b
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Dim f As Integer = a / b
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Console.Write(a.ToString() + " + " + b.ToString())
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Console.WriteLine(" = " + c.ToString.PadLeft(3))
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Console.Write(a.ToString() + " * " + b.ToString())
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Console.WriteLine(" = " + d.ToString.PadLeft(3))
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Console.Write(a.ToString() + " - " + b.ToString())
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Console.WriteLine(" = " + e.ToString.PadLeft(3))
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Console.Write(a.ToString() + " / " + b.ToString())
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Console.WriteLine(" = " + e.ToString.PadLeft(3))
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Console.ReadLine()
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'Ask the question, does the user wish to continue? Unfortunately it
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'is case sensitive.
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Console.Write("Would you like to continue? (yes / no)")
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'The program grabs the variable and prints and starts again.
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answer = Console.ReadLine
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'The command for the variable to work would be in this case "yes"
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Loop While answer = "yes"
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End Sub
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'Seven
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Private Sub UsingForLoops()
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'Sometimes the program only needs to run once.
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'In this program we'll be counting down from 10.
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Console.Title = "Using For Loops | Learn X in Y Minutes"
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'Declare Variable and what number it should count down in Step -1,
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'Step -2, Step -3 ect.
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For i As Integer = 10 To 0 Step -1
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Console.WriteLine(i.ToString) 'Print the value of the counter
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Next i 'Calculate new value
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Console.WriteLine("Start") 'Lets start the program baby!!
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Console.ReadLine() 'POW!! - Perhaps I got a little excited then :)
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End Sub
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'Eight
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Private Sub ConditionalStatement()
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Console.Title = "Conditional Statements | Learn X in Y Minutes"
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Dim userName As String = Console.ReadLine
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Console.WriteLine("Hello, What is your name? ") 'Ask the user their name.
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userName = Console.ReadLine() 'Stores the users name.
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If userName = "Adam" Then
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Console.WriteLine("Hello Adam")
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Console.WriteLine("Thanks for creating this useful site")
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Console.ReadLine()
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Else
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Console.WriteLine("Hello " + userName)
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Console.WriteLine("Have you checked out www.learnxinyminutes.com")
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Console.ReadLine() 'Ends and prints the above statement.
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End If
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End Sub
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'Nine
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Private Sub IfElseStatement()
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Console.Title = "If / Else Statement | Learn X in Y Minutes"
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'Sometimes its important to consider more than two alternatives.
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'Sometimes there are a good few others.
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'When this is the case, more than one if statement would be required.
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'An if statement is great for vending machines. Where the user enters a code.
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'A1, A2, A3, ect to select an item.
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'All choices can be combined into a single if statement.
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Dim selection As String = Console.ReadLine 'Value for selection
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Console.WriteLine("A1. for 7Up")
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Console.WriteLine("A2. for Fanta")
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Console.WriteLine("A3. for Dr. Pepper")
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Console.WriteLine("A4. for Diet Coke")
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Console.ReadLine()
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If selection = "A1" Then
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Console.WriteLine("7up")
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Console.ReadLine()
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ElseIf selection = "A2" Then
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Console.WriteLine("fanta")
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Console.ReadLine()
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ElseIf selection = "A3" Then
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Console.WriteLine("dr. pepper")
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Console.ReadLine()
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ElseIf selection = "A4" Then
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Console.WriteLine("diet coke")
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Console.ReadLine()
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Else
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Console.WriteLine("Please select a product")
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Console.ReadLine()
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End If
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End Sub
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End Module
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```
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## References
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I learnt Visual Basic in the console application. It allowed me to understand the principles of computer programming to go on to learn other programming languages easily.
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I created a more indepth <a href="http://www.vbbootcamp.co.uk/" Title="Visual Basic Tutorial">Visual Basic tutorial</a> for those who would like to learn more.
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The entire syntax is valid. Copy the and paste in to the Visual Basic compiler and run (F5) the program.
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