AObjectis a combination of code and data that can be treated as a unit. An object can be part of an application, like a control or a form. A complete application can also be an object.
When you create an application in Visual Basic, you work with objects all the time. You can use objects provided by Visual Basic such as B. Controls, forms, and data access objects. You can also use objects from other applications in your Visual Basic application. You can even create your own objects and define additional properties and methods for them. Objects act like ready-made building blocks for programs - you can write a piece of code once and use it again and again.
This topic describes objects in detail.
objects and classes
Every object in Visual Basic is represented by aClassAre defined. A class describes an object's variables, properties, procedures, and events. Objects are instances of classes. You can create as many objects as you need once you have defined a class.
To understand the relationship between an object and its class, imagine cookie cutters and cookies. The cookie cutter is the class. It defines the characteristics of each biscuit, e.g. the size and shape. The class is used to create objects. The objects are the cookies.
You must create an object before you can access its members, except for elementsSharedwhich can be accessed without an object of the class.
Creating an object from a class
Determine which class you want to create an object from, or define your own class. Example:
Public Class Customer Public Property AccountNumber As IntegerEnd Class
Write adim statementto create a variable to which you can assign a class instance. The variable should be of the type of the desired class.
Dim nextCustomer As Customer
Add the keywordNew operatorto initialize the variable for a new instance of the class.
Dim nextCustomer As New Customer
You can now access the members of the class through the object variable.
nextCustomer.AccountNumber = lastAccountNumber + 1
Whenever possible, you should declare the variable to be of the class type you intend to assign to it. This is calledearly bindingdesignated. If you don't know the class type at compile time, you canLate Bindingcall by replacing the variable with theobject data typedeclare. However, late binding can result in performance degradation and limitations on access to the run-time object's members. For more information, seeObject Variable Declaration.
Newly created objects from a class are often identical. However, once they exist as individual objects, their variables and properties can be modified independently of the other instances. For example, if you add three check boxes to a form, each check box object is an instance of the classCheckBox. The single onesCheckBox-Objects share a common set of characteristics and functions (properties, variables, procedures, and events) defined by class. However, each has its own name, can be turned on and off separately, and placed elsewhere on the form.
An object is an element of an application, the oneinstancerepresents a class. Fields, properties, methods, and events are the building blocks of objects and make up theirsMember.
You access a member of an object by sequentially specifying the object variable name, a period (
.) and specify the name of the member. In the following example, theText-Property of aLabel-Object set.
warningLabel.Text = "Data not saved"
IntelliSense collection of members
IntelliSense lists the members of a class when you invoke the List Members option, such as when you type a period (
.) as the member access operator. If you type the period after the name of a variable that was declared as an instance of that class, IntelliSense lists all instance members and none of the shared members. If you type the period after the class name itself, IntelliSense lists all shared members and none of the instance members. For more information, seeUsing IntelliSense.
fields and properties
FelderandCharacteristicsrepresent the information contained in an object. You get their values and set them with assignment statements just as you get and set local variables in a procedure. The following example calls theWidthproperty and sets theForeColor-Property of aLabel-object.
Dim warningWidth As Integer = warningLabel.WidthwarningLabel.ForeColor = System.Drawing.Color.Red
Note that a field can also be used as aMembervariablereferred to as.
Use property procedures in the following cases:
You must control when and how a value is set or retrieved.
The property has a well-defined set of values that need to be validated.
Setting the value results in a perceptible change in the object's state, e.g
Setting the property results in changes to other internal variables or the values of other properties.
A number of steps must be performed before the property can be set or retrieved.
Use fields in the following cases:
The value is that of a self-checking type. Example: An error or automatic data conversion occurs if a value other than
Booleanvariable is assigned.
Any value in the range supported by the data type is invalid. This applies to many properties of type
The property is a
String- Data type, and there is no constraint on the size or value of the string.
For more information, seeProperty Procedures(property procedures).
Always keep the non-constant fields private. If you want to make it public, use a property instead.
OneMethodis an action that can be performed by an object. For example, isAdda method ofComboBoxobject that adds a new entry to a combo box.
The following example demonstrates the use of theStart-Method oneTimer-object shown.
Dim safetyTimer As New System.Windows.Forms.TimersafetyTimer.Start()
Note that a method is simply aProcedureis provided by an object.
For more information, seeprocedures.
An event is an action recognized by an object, such as a mouse click or key press, and for which you can write code in response. Events can occur as a result of user action, program code, or be caused by the system. Code that signals an event is said to be the eventtrigger, and code that responds to it shouldtransact.
You can also develop your own custom events to be raised by your objects and handled by other objects. For more information, seeevents.
When you create an object from a class, the result is an instance of that class. Members that don't match the keywordApprovedare declaredinstance members, which belong exclusively to this entity in question. An instance member in one instance is independent of the same member in another instance of the same class. For example, an instance member variable can have different values in different instances.
Items tagged with the keyword
Sharedare declaredshared membersthat belong to a class as a whole and not to a specific instance. A shared member exists only once, regardless of how many instances you create of its class, or whether you create no instances. For example, a shared member variable contains only one value that is available to all code that can access the class.
Make sure the object is created from its class and assigned to an object variable.
Dim secondForm As New System.Windows.Forms.Form
In the statement that accesses the element, follow the object variable name with theMemberzugriffsoperator(
.) and then the member name.
Follow the class name with theMemberzugriffsoperator(
.) and then the member name. You should have one
Shared-Always call the member of the object directly via the class name.
Console.WriteLine("This computer is called " & Environment.MachineName)
Alternatively, if you have already created an object from the class, you can create a
Shared-Call members via the object's variable.
Differences between classes and modules
The main difference between classes and modules is that classes can be instantiated as objects while standard modules cannot. Since there is only one copy of a standard module's data, when one part of your program changes a public variable in a standard module, every other part of the program gets the same value when it subsequently reads that variable. In contrast, object data exists separately for each instantiated object. Another difference is that unlike standard modules, classes can implement interfaces. If a class with theMustInherit modifieris marked, it cannot be instantiated directly. However, it is still different from a module as it can be inherited while modules cannot be inherited.
Sharedmodifier is applied to a class member, it is associated with the class itself rather than with a specific instance of the class. The member is invoked directly using the class name, in the same way as module members.
Classes and modules also use different scopes for their members. Members defined within a class are scoped to a specific instance of the class and exist only for the lifetime of the object. To access class members from outside a class, you must use fully qualified names in the formatObject.Memberuse.
On the other hand, by default, the members declared in a module can be called publicly and with any code that can call the module. This means that variables in a standard module are ultimately global variables since they are visible anywhere in the project and exist for the lifetime of the program.
Reuse of classes and objects
With objects, you can declare variables and procedures once and then reuse them whenever you need to. Example: If you want to add a spell checker to an application, you can define all the variables and support functions to provide the spell checker functionality. If you create your spell checker as a class, you can then reuse it in other applications by adding a reference to the compiled assembly. You might even be able to save yourself some work by using a spell checker class someone else has already developed.
.NET provides many examples of components that are available for use. The following example uses theTimeZone-class inSystem-Namespace.TimeZonecontains members that enable you to retrieve information about the current computer system's time zone.
Public Sub ExamineTimeZone() Dim tz As System.TimeZone = System.TimeZone.CurrentTimeZone Dim s As String = "Current time zone is " s &= CStr(tz.GetUtcOffset(Now).Hours) & " hours and " s &= CStr(tz.GetUtcOffset(Now).Minutes) & " minutes " s &= "different from UTC (coordinated universal time)" s &= vbCrLf & "and is currently " If tz.IsDaylightSavingTime(Now) = False Then s &= "not " s &= "on ""summer time""." Console.WriteLine(s)End Sub
In the previous example, declares the firstdim statementan object variable of typeTimeZoneand shows them to youTimeZone-Object added by theCurrentTimeZoneproperty was returned.
relationships between objects
Objects can be linked to each other in different ways. The basic types of relationships arehierarchicalandinclusion.
When classes derive from more basic classes, ahierarchical relationshipspoken. Class hierarchies are useful when describing members that are a subtype of a more general class.
In the example below, let's assume you want a special kind of oneButton-Define elements that look like a normalButtonelement, but also provides a method that inverts the foreground and background colors.
Define a class that derives from an already existing class
Use oneclass statementto define a class from which to create the required object.
Public Class ReversibleButton
Make sure the last line of code in the class is a
End Class-Instruction follows. By default, the integrated development environment (IDE) generates a
Class-Instruction must be immediatelyinherits statementconsequences. Specify the class from which your new class is derived.
Your new class inherits any members defined by the base class.
Add the code for the additional members that your derived class exposes. For example, you can
ReverseColorsmethod and the derived class could look like this:
Public Class ReversibleButton Inherits System.Windows.Forms.Button Public Sub ReverseColors() Dim saveColor As System.Drawing.Color = Me.BackColor Me.BackColor = Me.ForeColor Me.ForeColor = saveColor End SubEnd Class
If you select an object from the
ReversibleButtoncreate a class, it can access all members of theButtonclass, as well as the method and any other new elements that
Derived classes inherit members from the class on which they are based. This allows you to add complexity when navigating through a class hierarchy. For more information, seeFundamentals of Inheritance.
compiling the code
Make sure the compiler can call the class you want your new class to derive from. This can involve fully qualifying the name, as in the previous example, or identifying the namespace in aImports statement (.NET namespace and type). If the class is in another project, you may need to add a reference to the project. For more information, seeManaging references in a project.
Another way to link objects is ainclusion relationship. Container objects logically enclose other objects. For example, this containsOperatingSystem-object oneVersion-Object logical it through itsVersionproperty returns. Note that the container object does not physically contain any other object.
A specific type of object containment is represented bylistings. Collections are groups of similar objects that can be listed. Visual Basic supports a specific syntax in theFor Each... Next Statementthat you to iterate through the items of a collection. In addition, collections allow the use of aItem-Elements to retrieve elements by their index or by mapping to a unique string. Collections are easier to use than arrays because you can use them to add or remove elements without indexes. Because of their ease of use, collections are often used to store forms and controls.
Walkthrough: Defining Classes
Provides a step-by-step description of creating a class.
Overloaded properties and methods
Overloaded properties and methods
Fundamentals of Inheritance
Describes the inheritance modifiers, method and property overrides, MyClass, and MyBase.
Object Lifetime: Creation and destruction of objects
Explains how to create and remove class instances.
Anonymous The type
Describes how to create and use anonymous types, which allow you to create objects without writing a class definition for the data type.
Object initializers: named and anonymous types
Explains object initializers used to create instances of named and anonymous types with a single expression.
How to: Infer property names and types in declarations from anonymous types
Explains how to infer property names and types in declarations from anonymous types. Provides examples of successful and failed derivations.
VB is intended to be easy to learn and fast to write code with; as a result, it is sometimes called a rapid application development (RAD) system and is used to prototype an application that will later be written in a more difficult but efficient language.Which is an example of Visual Basic objects answer? ›
Examples are water, mirror ( polished glass ) , well polished metals placed in door locks , your own phone etc the things which reflects your image clearly .What are objects and classes in Visual Basic? ›
Each object in Visual Basic is defined by a class. A class describes the variables, properties, procedures, and events of an object. Objects are instances of classes; you can create as many objects as you need once you have defined a class.How long does it take to learn Visual Basic? ›
The time it takes for most learners to gain a solid understanding of VBA falls somewhere within the range of one to eight weeks. While this number depends on many factors, most learners who devote several solid weeks to working with VBA will be able to write basic code.Is Visual Basic Dead? ›
Microsoft updated its programming languages strategy, confirming that Visual Basic will remain a going concern even though it's still relegated to second-rate status when compared to C# and F#.Is Visual Basic still in demand? ›
In fact, VB remains one of the most popular programming languages. Companies all over the world rely on VB programmers to develop applications to perform critical business functions. Visual Basic is a must-have skill if you're interested in becoming a business-to-business (B2B) software developer.Is Visual Basic simple? ›
Visual Basic is a type-safe programming language that's designed to be easy to learn.Who uses Visual Basic? ›
Today, VBA is the most popular version of Visual Basic. Microsoft has used it to develop Microsoft Office apps such as Excel and PowerPoint.
Visual Basic is an object-oriented programming language developed by Microsoft. Using Visual Basic makes it fast and easy to create type-safe .What are the 3 object classes? ›
An object class can be one of three types, structural, abstract, and auxiliary.
For example: in real life, a car is an object. The car has attributes, such as weight and color, and methods, such as drive and brake. A Class is like an object constructor, or a "blueprint" for creating objects.What is class vs object example? ›
Class can only be declared once. Object can be created many times as per requirement. Example of class can be car. Objects of the class car can be BMW, Mercedes, jaguar, etc.Can you learn VBA in one day? ›
A one day course designed to get you started with VBA / Excel Macros. This course is designed to teach experienced users of Excel how to automate spreadsheets. If you would prefer a more in-depth course we also offer a 2 day VBA course.Is Visual Basic good for beginners? ›
Visual Basic is an object-oriented programming language and a programming environment. It offers a graphical user interface (GUI) for an easy user experience. This user-friendly GUI makes the language an excellent choice for beginners.Is Visual Basic high level? ›
The Microsoft® Visual Basic® programming language is a high-level programming language for the Microsoft . NET Framework. Although it is designed to be an approachable and easy-to-learn language, it is also powerful enough to satisfy the needs of experienced programmers.What has replaced Visual Basic? ›
NET Framework. Microsoft launched VB.NET in 2002 as the successor to its original Visual Basic language, the last version of which was Visual Basic 6.0.Is Visual Basic still used in Excel? ›
Visual Basic for Application is a human-readable and editable programming code that gets generated when you record a macro. Today, it is widely-used with other Microsoft Office applications such as MS-Word, MS-Excel, and MS-Access.Why did Microsoft abandon Visual Basic? ›
According to Lucas, Microsoft made an “unforced error” when it released VB.NET in 2002. Although the language was similar, there was no migration path, and new . NET features such as full object orientation were not wanted by VB developers. Usage dropped, and today VB.NET is a poor cousin to C#, which dominates .What is better than Visual Basic? ›
Solution 2. When you will go for a job in Programming then C# will be the better choice. If you first want to learn then VB could be the better choice - it depends on what is better readable for you. In both cases : what you have to learn is not the programming-language - what you have to learn is the use of the .
As digital technology is an inseparable part of modern data collection and analysis processes, Visual Basic for Application (VBA) skills are important in most fields. Recruiters frequently look for key VBA development skills when reviewing resumes.Does Visual Basic use Python? ›
Features of Visual Basic
It's a Cross-platform language which can be written on Mac, Linux, Windows and in other operating systems with Python interpreter installed. Supports cross-platform development on Android, iOS, Windows Universal Platform and the Mac in C# via Xamarin since Visual Studio 2015.
Visual Basic is a Compiled Programming Language, while Python is an Interpreted Programming Language.Is C++ used anymore? ›
There are many different kinds of jobs out there that require C++ language. It is a versatile language, so it remains in high demand amongst professionals, such as software developers, game developers, C++ analysts and backend developers, etc.What is Visual Basic mostly used for? ›
VBA is used to write programs for the Windows operating system and runs as an internal programming language in Microsoft Office (MS Office, Office) applications such as Access, Excel, PowerPoint, Publisher, Word, and Visio.What language does Excel use? ›
VBA is an abbreviation for Visual Basic for Application. VBA is a programming language that was developed by Microsoft Corp., and it is integrated into the major Microsoft Office applications, such as Word, Excel, and Access.Is Visual Basic for free? ›
A free, fully featured, and extensible solution for individual developers to create applications for Android, iOS, Windows, and the web.What level of programming is Visual Basic? ›
Visual Basic is a high level programming language which evolved from the earlier DOS version called BASIC. BASIC means “Beginners All-purpose Symbolic Instruction Code”. Visual Basic is an example of a graphical-based language. A graphical-based language allows the user to work directly with graphics.What are the skills of Visual Basic? ›
In a Visual Basic course, students might learn about the user interface, language syntax, program structure, and implementation of the programming language. The objective of such a course is to learn to create and use applications.Can you make games in Visual Basic? ›
You can write for a casino simulation games like slot machine, board games like snake and ladder chess, educational games , games that test your IQ, multimedia players and more.
In computer programming, the object class refers to a class created to group various objects which are instances of that class. Classes are code templates for creating objects. In cases where objects need to be grouped in a certain way, an object class is the “container” for a set of objects built on these templates.What is a class vs object in coding? ›
Class vs Object
A class is a blueprint for declaring and creating objects. An object is a class instance that allows programmers to use variables and methods from inside the class. Memory is not allocated to classes. Classes have no physical existence.
Object is an instance of a class. Class is a blueprint or template from which objects are created. 2) Object is a real world entity such as pen, laptop, mobile, bed, keyboard, mouse, chair etc. Class is a group of similar objects.How many types of object classes are there? ›
Object classes fall into three categories: abstract, structural, and auxiliary: Abstract classes are those that may specify a set of required and optional attribute types, but that are only intended to be used if they are extended by other object classes.What is a real life example of a class object? ›
An object is a real-life entity that is defined as an instance of a class. The objects of a class called Animals, for example, will be a cat, dog, elephant, and so on. Each object has its own identity, attribute, and behavior.Is it always necessary to create objects from class? ›
No, it is not always necessary to create objects from a class. However, in object-oriented programming, objects are typically created from classes, as classes define the properties and behaviors of the objects, and only creating an object makes it possible to access the attributes and functions of the class.What is the example of class and object in VB net? ›
Objects are the basic run-time units of a class. Once a class is defined, we can create any number of objects related to the class to access the defined properties and methods. For example, the Car is the Class name, and the speed, mileage, and wheels are attributes of the Class that can be accessed by the Object.What is object in programming? ›
An object stores its state in fields (variables in some programming languages) and exposes its behavior through methods (functions in some programming languages). Methods operate on an object's internal state and serve as the primary mechanism for object-to-object communication.What is an example of object type? ›
An object type can represent any real-world entity. For example, an object type can represent a student, bank account, computer screen, rational number, or data structure such as a queue, stack, or list.Is Excel VBA harder than Python? ›
Python is easier to learn and master, unlike Excel, which includes a personalized language known as VBA that is complex to master and execute.
Because VBA is the programming language built into most Microsoft Office applications, the more familiar you are with the Microsoft environment, particularly Excel, the easier it will be for you to learn VBA.Is Excel VBA easier than Python? ›
In summary, if your focus is on automating and customizing Microsoft Office applications, then VBA is likely the better choice. However, if you need a more general-purpose programming language that can be used for a variety of tasks, then Python may be the better option.Which is better Python or Visual Basic? ›
Why is Visual Basic Faster than Python? The main reason why VB is faster than Python is that python is an interpreted language. An interpreted language can be slow? Yes, it can be, because interpretation needs to process each instruction before creating and executing into the machine code.Which is better Java or Visual Basic? ›
VB.NET requires a window license. Java is an open-source framework. Whereas, VB.NET uses a default IDE that is Microsoft Visual studio for developing an application. Java has various IDE for developing a java-based application such as Eclipse, NetBeans, IntellJ IDE that makes the development process more comfortable.What language is VBA similar to? ›
VBA and C++ have similar data types, but they do not all have the same names. The table below shows some equivalent data types in the two languages. The following arithmetic and relational operations are the same in C++ and VBA: + – * < <= => and >.How difficult is Visual Basic? ›
It is easy to learn and does not require you to memorize difficult commands like other programming languages. In this course, you will learn how to write Windows applications and programs using the Visual Basic programming language and the Visual Basic development environment.Is Visual Basic low code? ›
Most software applications developed by low-code means are Web applications or mobile apps. Think of a low-code platform as the next generation of rapid application development (RAD) tools such as Visual Basic, Visual Studio, and Delphi.Is Visual Basic low level? ›
The Microsoft® Visual Basic® programming language is a high-level programming language for the Microsoft .Why is Visual Basic easy to learn? ›
History of Visual Basic
Unlike other programming languages, BASIC language incorporated several common English words into its syntax. This made the language more user-friendly as end-users found it easier to learn and remember.
Along with C# and F#, it is one of the three main languages targeting the . NET ecosystem. Microsoft updated its VB language strategy on 6 Feb 2023 stating that VB is a stable language now and Microsoft will keep maintaining it.
Gambas. Gambas is a name of the platform, BASIC is the language, Gambas is also the IDE and the GUI designer of Gambas programming platform. It is the one created as a complete replacement to Microsoft Visual Basic for GNU/Linux. Programs created with Gambas can run mainly on GNU/Linux.Which is easy C# or Visual Basic? ›
VB (Visual Basic.NET) is quite a simple language to understand for it resembles the basic English language. Unlike other languages including C#, it mostly uses words like AND. C#, on the flip side, is a part of the C family and owns the features of Python, Java, and C++.How common is Visual Basic? ›
Visual Basic net may not be the trendiest programming language to know, but it remains popular and has now hit its highest place on the Tiobe index of top computer languages. While the future of VB.Net is uncertain, it remains a viable market choice.What type of coding is Visual Basic? ›
Visual Basic is an object-oriented programming language developed by Microsoft. Using Visual Basic makes it fast and easy to create type-safe . NET apps.Is Visual Basic a powerful? ›
Visual Basic is one of the most important programming languages having a powerful front-end tool which is able to achieve simple and complex business requisites in and effective and efficient manner.