ASP.NET razor VB variable

May 12, 2021 ASP.NET

1. ASP.NET Razor - VB variable

2. Variable

3. The data type

4. Operator

5. Transform the data type

ASP.NET Razor - VB variable

Razor ASP.NET VB (Visual Basic) in the article, and this section explains VB variables.

Variables are named entities that are used to store data.

Variable

Variables are used to store data.

The name of a variable must begin with a letter character and cannot contain spaces or reserve characters.

A variable can be a specified type that represents the type of data it stores. The string variable stores string values ("Welcome w3cschool.cn"), the integer variable stores the numeric value (103), the date variable stores the date value, and so on.

Variables are declared using the Dim keyword, or by using a type if you want to declare a type, but ASP.NET usually automatically determines the data type.

// Using the Dim keyword:
Dim greeting = "Welcome to w3cschool.cn"
Dim counter = 103
Dim today = DateTime.Today

// Using data types:
Dim greeting As String = "Welcome to w3cschool.cn"
Dim counter As Integer = 103
Dim today As DateTime = DateTime.Today

The data type

Common data types are listed below:

type	describe	Example
integer	Integer (full number)	103, 12, 5168
double	64-bit floating point number	3.14, 3.4e38
decimal	Decimal number (high precision)	1037.196543
boolean	Boolean value	true, false
string	String	"Hello w3cschool.cn", "John"

Operator

The operator tells the ASP.NET what kind of commands are executed in the expression.

The VB language supports a variety of operators. Common operators are listed below:

Operator	describe	Example
=	Assign a variable.	i=6
+ - * /	Add a value or a variable. Lower a value or a variable. Multiply one value or a variable. Remove with a value or a variable.	i=5+5 i=5-5 i=5*5 i=5/5
+= -=	The variable is incremented. Variables are decremented.	i += 1 i -= 1
=	equal.Returns true if the value is equal.	if i=10
<>	Not equal.Returns true if the value is inequal.	if <>10
< > <= >=	Smaller than. more than the. It is less than or equal. greater or equal to.	if i<10 if i>10 if i<=10 if i>=10
&	Connect strings (a series of interrelated things).	"w3" & "schools"
.	Dot number.Separate objects and methods.	DateTime.Hour
()	Parentheses.Group values.	(i+5)
()	Parentheses.Transfer parameters.	x=Add(i,5)
()	Parentheses.Access the value of an array or a collection.	name(3)
Not	No.Real / false.	if Not ready
And OR	Logic and. Logic or.	if ready And clear if ready Or clear
AndAlso orElse	Extended logic and. Extended logic or.	if ready AndAlso clear if ready OrElse clear

Transform the data type

It is sometimes useful to convert from one data type to another.

The most common example is converting string input to another type, such as an integer or date.

In general, user input is treated as string processing, even if the user enters a number. The numeric input must therefore be converted to a number before it can be used for calculations.

The common conversion methods are listed below:

method	describe	Example
AsInt() IsInt()	The conversion string is an integer.	if myString.IsInt() then myInt=myString.AsInt() end if
AsFloat() IsFloat()	The conversion string is the floating point number.	if myString.IsFloat() then myFloat=myString.AsFloat() end if
AsDecimal() IsDecimal()	The conversion string is a decimal number.	if myString.IsDecimal() then myDec=myString.AsDecimal() end if
AsDateTime() IsDateTime()	The conversion string is the ASP.NET DATETIME type.	myString="10/10/2012" myDate=myString.AsDateTime()
AsBool() IsBool()	The conversion string is the Boolean value.	myString="True" myBool=myString.AsBool()
ToString()	Convert any data type as a string.	myInt=1234 myString=myInt.ToString()

These are the basics of variables, operators, data types, and transformations of data types related to VB variables in this section.