Aquariums Visual Basic Programming Blog

Use: Optional Program code to be executed within the procedure. Description Defines a subroutine Rules at a Glance Subroutines cannot be nested; that is, you cannot define one subroutine inside another subroutine. (This applies to all procedures.) If you do not include one of the accessmodifier keywords, a subroutine will be Publicby default. Any number of ExitSub statements can be placed within the subroutine. Execution will continue with the line of code immediately following the call to the subroutine. If you specify an optional parameter in your subroutine declaration, you must also provide a default value for that parameter. For example: Private Sub ShowMessage(Optional sMsg _ As String = “Not given”) A subroutine is called by using its name and enclosing any arguments in parentheses. For example, a routine named SomeRoutine might be called as follows: x = 12 y = 12 SomeRoutine(x, y) Note that because it does not return a value, a subroutine cannot be assigned to a variable. For example, the following is illegal: z = SomeRoutine(x, y) Programming Tips and Gotchas There is often confusion between using the ByRef and ByVal methods of assigning arguments to the Sub procedure. ByRef assigns the reference of the variable in the calling procedure to the variable in the Sub procedure; that is, it passes a pointer containing the address in memory of the variable in the calling procedure. As a result, any changes made to the variable from within the Sub procedure are in reality made to the variable in the calling procedure. On the other hand, ByVal assigns the value of the variable in the calling procedure to the variable in the Sub procedure; that is, it makes a separate copy of the variable in a separate memory location. Changes made to the variable in the Sub procedure have no effect on the variable in the calling procedure. In general, ByRef arguments within class modules take longer to handle, since marshaling back and forth between Sub procedure and calling module must take place. So unless you explicitly need to modify a variable’s value within a Sub procedure, it’s best to pass parameters by value. VB .NET/VB 6 Differences If you do not specify whether an individual element in arglist is passed ByVal or ByRef, it is passed by reference in VB 6. In VB .NET, it is passed by value. If a parameter array is used in VB 6, it is an array of variants. In VB .NET, since the Variant is no longer supported, it must be an array of objects. In VB 6, a Sub procedure was called either by using the Call statement and including procedure arguments in parentheses or by using the name of the procedure and including
Quick Hint: If you are looking for best quality webspace to host and run your tomcat application check Vision tomcat hosting services

ByVal Use: Optional Type: Keyword The argument is passed by value; that is, the local copy of the variable is assigned the value of the argument. ByVal is the default method of passing variables. ByRef Use: Optional Type: Keyword The argument is passed by reference; that is, the local variable is simply a reference to the argument being passed. All changes made to the local variable will be also reflected in the calling argument. ParamArray Use: Optional Type: Keyword Indicates that the argument is an optional array of variants containing an arbitrary number of elements. It can only be used as the last element of the argument list, and it cannot be used with the ByRef, ByVal, or Optional keywords. varname Use: Required Type: String literal The name of the local variable containing either the reference or value of the argument. type Use: Optional Type: Keyword The data type of the argument. It can be Boolean, Byte, Char, Date, Decimal, Double, Integer, Long, Object, Short, Single, String, a user-defined type, or an object type. defaultvalue Use: Optional Data Type: Any For optional arguments, you must specify a default value. statements

Note: If you are looking for good and affordable webspace to host and run your servlet application check Sandzak servlet hosting services

Shadows In a derived class definition, indicates that calls to derived class members that are made through a base class ignore the shadowed implementation. Shared Callable without creating an object of the class. It is, in this strange sense, shared by all objects of the class. These are also called static subroutines. AccessModifier Use: Optional The possible values of AccessModifier are Public, Private, Friend, Protected, or ProtectedFriend. The following table describes the effects of the various access modifiers. Note that “direct access” refers to accessing the member without any qualification, as in: classvariable = 100 and “class/object access” refers to accessing the member through qualification, either with the class name or the name of an object of that class. For more information, see Section 3.7 in Chapter 3. Direct access scope Class/object access scope Private Declaring class Declaring class Protected All derived classes Declaring class Friend Derived in-project classes Declaring project Protected Friend All derived classes Declaring project Public All derived classes All projects name Use: Required Type: String literal The name of the Sub procedure. arglist Use: Optional Data Type: Any A comma-delimited list of variables to be passed to the sub procedure as arguments from the calling procedure. arglist uses the following syntax and parts: [Optional] [ByVal | ByRef] [ParamArray] varname[( )] _ [As type] [= defaultvalue] Optional Use: Optional Type: Keyword An optional argument is one that need not be supplied when calling the function. However, all arguments following an optional one must also be optional. A ParamArray argument cannot be optional.

Hint: If you are looking for very good and affordable webspace to host and run your j2ee hosting application check Sandzak.com j2ee web hosting services

Related items of information are often stored in multiple arrays (or in a multidimensional array). However, it is often preferable to store related data in a single array of structures. The Structure statement is often used to define a data structure capable of retrieving, storing, and saving fixed-length records. However, this is complicated by the absence of support for explicitly declared fixed-length strings in VB.NET. One solution is to use the attribute, where length is the fixed length of the string, when defining a member of type String. This instructs the VB .NET compiler to enforce a particular string length for the structure. For example: Structure Person Public FName As String Public MName As String Public LName As String Public Age As Short End Structure VB .NET/VB 6 Differences The Structure…EndStructure construct is new to VB .NET. It replaces the Type…EndType construct in VB 6. VB 6 user-defined types are different than VB .NET structures. A VB 6 user-defined type is simply a composite data type that combines multiple data types; it allows the user-defined type to be treated as a contiguous, word- or double-word aligned block of memory. A VB .NET structure is in some sense a hybrid object that combines data types and methods; ordinarily, no assumptions should be made about its layout in memory. In VB 6, the declaration of user-defined type members did not permit an access modifier. In VB .NET, it is required. Sub Statement Syntax [ClassBehavior] [AccessModifier] Sub name [(arglist)] [statements] [Exit Sub] [statements] End Sub ClassBehavior Use: Optional Type: Keyword One of the keywords shown in the following table: Keyword Description Overloads Indicates that more than one declaration of this subroutine exists (with different argument signatures). Overrides For derived classes, indicates that the subroutine overrides the subroutine by the same name (and argument signature) in the base class. Overridable Indicates that the subroutine can be overridden in a derived class. NotOverridable Indicates that the subroutine cannot be overridden in a derived class. MustOverride Indicates that the subroutine must be overridden in a derived class.

Hint: This post is supported by Gama web hosting php mysql provider

Method member declarations End Structure Description Used to declare user-defined types. Structures are similar to classes, but they are value types rather than reference types. Rules at a Glance The members of a structure can be variables, properties, methods, or events. Note, however, that each member must be declared with an access modifier: Public (or Dim), Private, or Friend. You cannot assign a structure member an initial value at the same time as you declare it. As a result, the following Structure construct is illegal: Structure Point Public x As Integer = 0 ‘ Illegal Public y As Integer = 0 ‘ Illegal End Structure Structure members can be other structures or objects. If a structure member is an array, it cannot be explicitly dimensioned. Structures can be passed as arguments to functions or as the return type of a function. Although structures are similar to classes, the following class features are not supported in structures: o Structures cannot explicitly inherit, nor can they be inherited. o All constructors for a structure must be parameterized. o Structures cannot define destructors. o Member declarations cannot include initializers, nor can they use the AsNew syntax or specify an initial array size. Example The simplest and most common use of structures is to encapsulate related variables. For instance, we might define a structure as follows: Structure strPerson Public Name As String Public Address As String Public City As String Public State As String Public Zip As String Public Age As Short End Structure To define a variable of type strPerson, we write (as usual): Dim APerson As strPerson To access a member of a structure, we use the dot syntax, as in: APerson.Name = “Beethoven” Programming Tips and Gotchas

Hint: If you are looking for high quality and reliable webspace provider to host and run your jsp hosting application check Sandzak jsp web hosting provider

Returns a string that consists of the first character of character duplicated number times Example The line: MsgBox(StrDup(Number:=5, Character:=”ABC”)) displays “AAAAA”. VB .NET/VB 6 Differences The StrDup function is new to VB .NET. It appears in part to be a replacement for the String function. StrReverse Function Class Microsoft.VisualBasic.Strings Syntax StrReverse(expression) expression Use: Required Data Type: String The string whose characters are to be reversed Return Value String Description Returns a string that is the reverse of the string passed to it. For example, if the string and is passed to it as an argument, StrReverse returns the string dna. Structure…End Structure Statement Syntax Public|Private|Friend] Structure StructureName Nonmethod member declarations
Hint: If you are looking for high quality webhost to host and run your jsp application check Vision web hosting jsp services

o Carriage Return Chr$(13) o Space Chr$(32) Programming Tips and Gotchas If you convert to proper case, StrConv converts the first letter of each word to uppercase regardless of whether that word is significant. Hence, “this is the time” becomes “This Is The Time,” even though “the” ordinarily would not be capitalized. VB .NET/VB 6 Differences Two conversion values supported by VB 6, VbUnicode and VbFromUnicode, have no equivalent in the VbStrConv enumeration. As a result, the function can no longer be used to convert ASCII to Unicode or Unicode to ASCII. See Also StrComp Function, StrDup Function, StrReverse Function StrDup Function Class Microsoft.VisualBasic.Strings Syntax StrDup(number,character) number Use: Required Data Type: Integer The number of times to duplicate the first character in string character Use: Required Data Type: String, Char, or Object containing a String or Char The String or Char whose first character is to be duplicated Return Value A String containing the character duplicated the specified number of times Description
Note: If you are looking for reliable and quality webspace company to host and run your servlet application check professional servlet hosting services

A String converted according to conversion. Description Performs special conversions on a string Rules at a Glance The following intrinsic conversion constants specify the type of conversion to perform: Constant Converts… VbStrConv.UpperCase The entire string to uppercase. VbStrConv.LowerCase The entire string to lowercase. VbStrConv.ProperCase The first letter of every word in str to an uppercase character. VbStrConv.Wide Narrow (single-byte) characters in str to wide (doublebyte) characters. VbStrConv.Narrow Wide (double-byte) characters in str to narrow (singlebyte) characters. VbStrConv.Katakana Hiragana characters in str to Katakana characters. VbStrConv.Hiragana Katakana characters in str to Hiragana characters. VbStrConv.LinguisticCasing Uses linguistic rules for casing. Can be used only with UpperCase and LowerCase. VbStrConv.None Performs no conversion on str. VbStrConv.SimplifiedChinese Traditional Chinese characters in str to Simplified Chinese. VbStrConv.TraditionalChinese Simplified Chinese characters in str to Traditional Chinese. You can combine some of these constants by adding them together or using a logical OR. For example: VbStrConv.UpperCase + VbStrConv.Wide The only restriction is that the constants must be mutually exclusive. For example, specifying the value: VbStrConv.UpperCase Or VbStrConv.ProperCase ‘ Error will produce an error. VbStrConv.Katakana and VbStrConv.Hiragana only apply to locales in Japanese. Use of these constants on systems using other locales generates runtime error 5, “Invalid procedure call or argument.” VbStrConv.Wide and VbStrConv.Narrow only apply to locales in the Far East. Use of these constants on systems using other locales will generate a runtime error. When determining the start of a new word to convert to proper case, StrConv recognizes the following characters as word separators: o Null Chr$(0) o Horizontal Tab Chr$(9) o Line-feed Chr$(10) o Vertical Tab Chr$(11) o Form Feed Chr$(12)
Note: If you are looking for good and quality webspace to host and run your java application check professional java hosting services

string1 = string2 0 string1 > string2 1 string1 or string2 is Null Null Programming Tips and Gotchas Using the comparison operators <, <=, >, and >= to compare strings performs a character-bycharacter binary comparison. The StrComp function can provide a significant performance improvement (in the neighborhood of 30% to 70%) over the comparison operators. See Also StrConv Function, StrDup Function, StrReverse Function StrConv Function Class Microsoft.VisualBasic.Strings Syntax StrConv(str, conversion[, localeID]) str Use: Required Data Type: String The string expression to convert conversion Use: Required Data Type: Constant of the VbStrConv enumeration One of the constants listed in Rules at a Glance. localeID Use: Optional Data Type: Integer The locale identifier to use for the conversion Return Value

Hint: If you are looking for high quality and reliable webspace provider to host and run your jsp hosting application check Sandzak jsp web hosting provider

StrComp Function Class Microsoft.VisualBasic.Strings Syntax StrComp(string1, string2[, compare]) string1 Use: Required Data Type: String Any string expression string2 Use: Required Data Type: String Any string expression compare Use: Optional Data Type: CompareMethod constant Either CompareMethod.Binary or CompareMethod.Text Return Value Integer Description Determines whether two strings are equal and, if not, which of two strings has the greater value Rules at a Glance The compare argument is one of CompareMethod.Binary or CompareMethod.Text. If no comparison is specified, VB uses the value of OptionCompare. The following table describes the possible return values from the StrComp function: Scenario Return value string1 < string2 -1
Note: If you are looking for cheap and inexpensive provider to host and run your tomcat application check professional tomcat hosting services