Home and Learn: VB Net Course
With Visual Basic, and most programming languages, what you are doing is storing things in the computer's memory, and manipulating this store. If you want to add two numbers together, you put the numbers into storage areas and "tell" Visual Basic to add them up. But you can't do this without variables.
So a variable is a storage area of the computer's memory. Think of it like this: a variable is an empty cardboard box. Now, imagine you have a very large room, and in this room you have a whole lot of empty cardboard boxes. Each empty cardboard box is a single variable. To add two numbers together, write the first number on a piece of paper and put the piece of paper into an empty box. Write the second number on a piece of paper and put this second piece of paper in a different cardboard box.
Now, out of all your thousands of empty cardboard boxes two of them contain pieces of paper with numbers on them. To help you remember which of the thousands of boxes hold your numbers, put a sticky label on each of the two boxes. Write "number1" on the first sticky label, and "number2" on the second label.
What have we just done? Well, we've created a large memory area (the room and the cardboard boxes), and we've set up two of the boxes to hold our numbers (two variables). We've also given each of these variables a name (the sticky labels) so that we can remember where they are.
Now examine this:
Dim number1 As Integer
Dim number2 As Integer
number1 = 3
number2 = 5
That's code from Visual Basic Net. It's VB's way of setting up (or declaring) variables.
Here's a breakdown of the variable Declaration:
Now that you have a basic idea of what variables are, let's write a little piece of code to test them out. First, though, let's have our first look at the coding window.
To make life easier, we're going to put a button on our form. When our button is clicked, a little message box will pop up. Fortunately, there's no coding to write for a button, and very little at all for a message box.
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