Assignment Guidance - vb.net

Question

This is the third week of my intro to programming class and I'm stuck. I can get it to run I just can't enter more than 1 number. This is a vb console app.
Module Module1
Sub Main()
Dim highestNumber As Integer = -1000000000
Dim lowestNumber As Integer = 100000000
Dim userInput As Integer
Console.WriteLine("Input your numbers and when you are done enter -99.")
Console.WriteLine("The app will then give the highest and lowest numbers entered.")
userInput = Console.ReadLine()
While userInput <> "-99"
If userInput >= highestNumber Then
highestNumber = userInput
ElseIf userInput <= lowestNumber Then
lowestNumber = userInput
End If
End While
Console.WriteLine("The highest number you entered is: " & highestNumber)
Console.WriteLine("The lowest number you entered is: " & lowestNumber)
Console.ReadLine()
End Sub
End Module

Answer 1

You're only executing ReadLine once, before the loop starts, so you only get to enter one number. As it currently stands, if you don't enter -99 then you have an infinite loop since you cannot change userInput inside the loop.
You need to put a copy of userInput = Console.ReadLine() at the end of the While loop so that a new value can be entered and the logic will be re-executed.
Also, you might as well remove the = signs from your tests. No point changing the highest/lowest unless the new number is actual higher/lower.

Answer 2

Move this line inside your while loop
userInput = Console.ReadLine()

Answer 3

Here's my solution. It checks the input of the user, if it's not an integer they can try again or enter -99 and get out... You can also change how many numbers a user enters by changing a few places where it shows 2, or declare a variable and set it and then use it...
Public Sub Main()
Dim userInput As Integer = 0
Dim lstInteger As New List(Of Integer)
Console.WriteLine("Input your numbers and when you are done enter -99." & Environment.NewLine & "The app will then give the highest and lowest numbers entered.")
Do Until userInput = -99
If Integer.TryParse(Console.ReadLine(),userInput) AndAlso userInput <> -99 Then
lstInteger.Add(userInput)
If lstInteger.Count = 2 Then Exit Do
userInput = 0
If Integer.TryParse(Console.ReadLine(), userInput) AndAlso userInput <> -99 Then
lstInteger.Add(userInput)
If lstInteger.Count = 2 Then Exit Do
Else
If userInput = -99 Then Exit Do Else Console.WriteLine("Please enter a number.")
End If
Else
If userInput <> - 99 AndAlso userInput = 0 Then
Console.WriteLine("Please enter a number.")
Else
Exit Do
End If
End If
Loop
If lstInteger.Count = 2 Then
Console.WriteLine("The highest number you entered is: " & lstInteger.Max.ToString)
Console.WriteLine("The lowest number you entered is: " & lstInteger.Min.ToString)
End If
Console.ReadLine()
End Sub