Place the following objects on this form. Use cut and paste to make the task easier. Value, HScroll2. Value, HScroll3. Value Label5. Value Label1. Value, - HScroll2. Value, - HScroll3. Value, 0, 0 Label3. Value, 0 Label4. Value 3. Use the Project Explorer window to return to your main form and double click example 2 in your menu to add the appropriate code. Save and backup. Naming conventions Up till now, we have often accepted default names, Text1, Label1, etc.
In a big project, this is not good practice as it makes the code harder to read or maintain. Naming conventions use a prefix of three lowerCase letters to identify the type of control, followed by a meaningful name. A variable can only hold one datatype. A program can have as many variables as you need but before you can use a variable it must be declared.
True or False e. Often called double-precision. Often called single-precision. Visual Basic includes many built-in functions intrinsic functions.
Some perform basic mathematical tasks. Others manipulate string data such as converting text to upperCase or lowerCase letters. An argument is a value you pass to a function so the function has data to work with. Function names have parentheses at the end to hold the function arguments. Even if a function has no arguments, the parenthesis are required. Two intrinsic functions include message boxes and input boxes.
Activity 3: Message and input boxes Message and input boxes are intrinsic functions in Visual Basic 6. Follow the instructions Add new form to menu at the end of Activity 1 to create a new form with a menu heading on the main form.
The user must acknowledge this box before doing anything else. Remarks are added in code to explain the purpose of a section of code or to add information for code maintenance. Activity 4 Create a calculator that can add, subtract, multiply and divide two numbers given by the user. Use a Format function to ensure answer is rounded off to two decimal places.
Ensure that it is not possible to divide by zero, either by entering nothing or by entering zero. Use the MsgBox function to indicate the problem to the user. If Val txtTwo. SetFocus The SetFocus method returns the cursor to the first input box. Set properties to pretty it up. Check that it works.
Use integers, very big numbers, very small numbers, negative numbers, zeros, etc. Is your label big enough for all values? Connect to a Binary Selection menu heading on the main form. Sequence algorithms The programs in Activities 1 — 3 were all constructed from sequence algorithm constructs. Each line of code followed another with only one possible pathway for each event. So, for each sub procedure, the algorithm would consist of input, output and a series of process steps, e.
Selection allows multiple pathways for any event and allows for choices to be made. Here is the syntax in Visual Basic.
Enter the measurement The measurement in centimetres is 2. Option buttons are mutually exclusive, i. Try it out with some test data including very large numbers, very small numbers, zero, negative numbers, 0. Multiway selection In Activity 5 we looked at an example of binary selection. If the selection involves more than two alternatives, you can use nested If statements but this becomes complicated and leads to hard-to-read code. It is better to use Case statements.
Here is the syntax for multiple selection through Case statements. The post office has the following charges for parcels based upon different weights. Use Case statements in your code. Link this as CaseWeights under the Multiway menu heading in your main form.
Use a set of check boxes to allow a user to choose the noise level by the comments, then output the probable decibel level based on information in the following table. Activity 7 A control array is a set of multiple controls of the same type with the same name often created by using the Copy and Paste command. You may have encountered this already in adding radio buttons or check boxes to your form.
Individual controls within the array are distinguished by having different Index property values. Try this out, then add code to change the label background colour to something appropriate for each different day.
Choose the. NET Core cross-platform development workload, and then choose Modify. Some of the screenshots in this tutorial use the dark theme. In the Create a new project window, choose Visual Basic from the Language list. Next, choose Windows from the Platform list and Console from the project types list. After you apply the language, platform, and project type filters, choose the Console Application template, and then choose Next.
If you do not see the Console Application template, you can install it from the Create a new project window. In the Not finding what you're looking for? Then, in the Visual Studio Installer, choose the. After that, choose the Modify button in the Visual Studio Installer. You might be prompted to save your work; if so, do so. Next, choose Continue to install the workload. Then, return to step 2 in this " Create a project " procedure.
Then, choose Next. In the Additional information window,. NET Core 3. If not, select. Then, choose Create. Next, choose Windows from the Platform list and Console from the Project types list. NET desktop development workload. NET 6. Let's create an app that prompts you for your name and then displays it along with the date and time.
Here's how:. Enter the following Visual Basic code immediately after the opening bracket that follows the Sub Main args As String line and before the End Sub line:.
Use the green Start button, or press F5 to build and run your first app. When the console window opens, enter your name. Your console window should look similar to the following screenshot:.
This code replaces the existing WriteLine statement. Then name the file CalculateThis. Enter the following code between the Module Program line and the End Module line:. Click CalculateThis to run your program. Then, in the Configure your new project window, type or enter CalculateThis in the Project name box. Enter the following code between the Module Program line and End Module line:. In Program.
Select the green Start button next to CalculateThis to run your program. Now that you've created an app, you might want to add it to a Git repository.
We've got you covered. Git is the most widely used modern version control system, so whether you're a professional developer or you're learning how to code, Git can be very useful.
There, you can find cheat sheets, a popular online book, and Git Basics videos. To associate your code with Git, you start by creating a new Git repository where your code is located.
The repository name auto-populates based on your folder location. By default, your new repository is private, which means you're the only one who can access it. Whether your repository is public or private, it's best to have a remote backup of your code stored securely on GitHub.
Even if you aren't working with a team, a remote repository makes your code available to you from any computer. You can use this icon to pull any incoming commits or push any outgoing commits.
You can also choose to view these commits first. The second icon with the pencil shows the number of uncommitted changes to your code.
You can select this icon to view those changes in the Git Changes window. To learn more about how to use Git with your app, see the Visual Studio version control documentation. Visual Basic is a type-safe programming language that's designed to be easy to learn.
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