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Editor to share with you how to use the VB.NET constant, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to understand it!

As diners living in this era, they are happy. Because of the emergence of various technologies, it helps them to easily complete the development of various program functions, reducing the work pressure. VB.NET constants are numeric values, characters, or strings given directly in the program. Assignment statements like this are often used in programs:

IntValue=3

StrFileName= "student.aspx"

Here, 3 and "student.aspx" are constants.

In Visual Basic.NET, there are several special constant users that should be aware of:

(1) Nothing: in VB.NET, when a variable representing an object is assigned to Nothing, it means that the object is no longer used, and VB.NET frees up the memory space occupied by the object. The method used is:

ObjMyObject=Nothing

(2) Null: when the value of a variable is Null, it indicates that the value of the variable is not valid data. If you describe a variable as a box, VB.NET gives it an initial value when no value is assigned to it (for example, if the user defines an integer VB.NET constant, its value is 0 before it is used); Null indicates that the value in the box is an invalid value.

(3) True: it means true.

(4) False: indicates false. True and False are commonly used in conditional statements.

Another VB.NET constant is defined with the Const keyword. You can define a special constant by using Const instead of Dim when defining a variable and assigning a value to the variable. This constant appears in the program as a variable, but its value cannot be changed during the execution of the program. Because it is an immutable variable, some people call it a constant, and some people call it a symbolic constant. You can define a symbolic constant that represents a path name in the following ways:

Const strPathName= "c:" windows "

In this way, in later programs, you can use strPathName to represent all "c:" windows "pathnames" without having to specify them every time. Moreover, if the program changes, the pathname will become "c:" windows "cindy", just change the above definition statement. If you don't use constants, you need to modify all the places in the program that involve this pathname.

In order to improve the efficiency of the program, it is recommended that users do not define VB.NET constants that do not need to be used, because all constants take up memory space to be saved. Once a constant is defined, the system is responsible for maintaining the constant throughout its lifetime. For large programs, it is common to define a constant file in which all the constants that will be used in the project are defined and included when needed. While this approach is good for reducing code complexity, one problem is that a program does not use all the constants in the include file. In this way, many constants are useless, but these constants still take up the server's memory space. Because in the network environment, the needs of customers are difficult to estimate, often very large, so when defining constants, it is necessary to consider clearly in order to ensure the efficiency of the program.

These are all the contents of the article "how to use VB.NET constants". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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