Loops - Adding Numbers - Visual Basic

Question

So the program has to add all the numbers from "x" to "y".

But it also has to display all the numbers added :

i.e. 10 to 20 should display 10 + 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 = 165

Here's what I have:

Dim firstnum As Integer = Val(TextBox1.Text)
    Dim secondnum As Integer = Val(TextBox2.Text)
    Dim sum As Integer = 0


    While firstnum <= secondnum

        sum = sum + firstnum
        firstnum = firstnum + 1

        Label3.Text = firstnum & "+"

    End While


    suum.Text = "  =  " & Val(sum)

Answer 1

With the following:

Label3.Text = firstnum & "+"

You are overwriting the value in Label3 every time you go through the loop. What you probably want to do is concatenate the existing value with the next number.

This should get you on your way:

Label3.Text = Label3.Text & firstnum & " + "

Answer 2

Is Linq ok? Then you can use Enumerable.Range and Enumerable.Sum:

Dim startNum = Int32.Parse(TextBox1.Text)
Dim endNum = Int32.Parse(TextBox2.Text)
Dim numbers = Enumerable.Range(startNum, endNum - startNum + 1) 'inclusive, therefore + 1
Label3.Text = String.Join(" + ", numbers)
suum.Text = numbers.Sum()