Getting Started

To start, open Visual Basic and then choose Console Application from the Templates list (see Figure 10.1).

Figure 10.1: Choose Console Application from the Templates list.

Next, we're going to add some code to the project.

Writing Some Code

The first line of code involves adding the Imports System.Console line to the application. This line must be present before Module Module1; your code should look like the following listing after you enter it:

Imports System.Console Module Module1 Sub Main() End Sub End Module

Next, we need to declare a couple of variables for the application:

Dim X,Y As Double

These variables are used to store the values that are being input by the user and should be placed after the Sub Main() line in the Code Editor. The code should look like the following list:

Imports System.Console Module Module1 Sub Main() Dim X, Y As Double End Sub End Module

Now, we're at a point to begin handling the input, but first, we need to let the user know that we are requesting information from them. We'll begin by using a Write() method to output text information, such as 'Please Enter First Number:'. Instead of WriteLine() , which actually creates an entire line with a carriage return, we'll use Write() so that we can leave our cursor immediately beyond the end of the line for the user input.

Here is the code with the Write() method added:

Imports System.Console Module Module1 Sub Main() Dim X, Y As Double Write("Please Enter First Number: ") End Sub End Module

Next, we're ready to handle the input from the user and store it in variable X . We can use the ReadLine() method to handle this input:

Imports System.Console Module Module1 Sub Main() Dim X, Y As Double Write("Please Enter First Number: ") X = ReadLine() End Sub End Module

We can repeat this same approach for output and input for variable Y :

Imports System.Console Module Module1 Sub Main() Dim X, Y As Double Write("Please Enter First Number: ") X = ReadLine() Write("Please Enter Second Number: ") Y = ReadLine() End Sub End Module

The final step for this section of the code is to add the numbers together and then display the output using the Write() and WriteLine() methods. We're using both methods because we'll use Write() to display text such as 'Your final answer is:', and then we'll use WriteLine() to actually display the answer:

Imports System.Console Module Module1 Sub Main() Dim X, Y As Double Write("Please Enter First Number: ") X = ReadLine() Write("Please Enter Second Number: ") Y = ReadLine() Write("Your final answer is: ") WriteLine(X + Y) End Sub End Module

If you run the application using Debug Start Without Debugging, you'll see output similar to Figure 10.2.

Figure 10.2: The code being executed.

We can check the input and output by entering values as prompted. Provide a value of 10 and then press the Enter key on the keyboard. Your window should now look like Figure 10.3.

Figure 10.3: The program is asking for additional input.

Enter a value of 20 and then press the Enter key. This moves the program through the input, and then it displays the final answer of 30 , as seen in Figure 10.4.

Figure 10.4: The answer is displayed.