Comparison of Visual Basic and Visual Basic .NET

Contents
Procedures
Zero-based arrays
Jagged Arrays
Variant data type is gone
True object-oriented programming
Change from COM to NET
Elementary geometry management via the Forms designer
Option Explicit by default
References

While programmers expected to be able to recompile their Visual Basic source to a .NET target, the reality of the situation was that Visual Basic .NET was a vastly different paradigm.variable=variable+1

can now be written as:

.WriteLine

Procedures

edit

A procedure call must have parentheses in Visual Basic .NET.

Visual Basic .NET requires a ByVal or ByRef specification for parameters. In Visual Basic the specification could be omitted, implying ByRef by default. Most development environments, such as Visual Studio .NET, will automatically insert a ByVal, so in effect the default is ByVal, not ByRef. There are tools to convert Visual Basic code to VB.NET, such as the Visual Basic Upgrade Wizard that was included in Visual Studio .NET 2002 and 2003. Conversion tools automatically insert a ByRef if necessary, preserving the semantics of the Visual Basic application.

Zero-based arrays

edit

Visual Basic 5.0 and 6.0 has traditionally employed zero-based arrays (the default lower bound), unless "Option Base 1" is declared. This was the source of many out-by-one errors in Visual Basic programs, especially when dealing with interoperability across program library boundaries. Although the .NET Common Language Runtime can support arrays with any base value, Visual Basic .NET and C# provide only zero-based arrays and lists, and the .NET Common Language Specification requires zero-based arrays for interoperability between .NET languages.

Jagged Arrays

edit

Visual Basic .NET introduced the concept of a jagged array, whereby the rows can have unequal length as opposed to the uniform length of arrays imposed on Visual Basic programmers.

Variant data type is gone

edit

In languages compiling down to .NET platform, types are strict. Whilst the runtime allows for anonymous object which don't have a pre-defined, named type, the type of a variable may not change over the course of its life-time, hence the need to drop the Variant data-type. However, type "Object" has somewhat similar behavior in practice.

True object-oriented programming

edit

Visual Basic was an object-based language. It supported classes, but not other concepts that would make it an object-oriented language. Visual Basic .NET is a true object-oriented language with the following features:

inheritance
function overloading

Although no language targeting .NET allows for multiple inheritance for classes—multiple inheritance of interfaces is supported.

Change from COM to NET

edit

Whilst the IDE does a reasonable job of hiding the fact, the dependence on ActiveX objects is dropped in Visual Basic .NET (although there are mechanisms for interfacing with COM in .NET ) in favour of .NET components offering similar functionality. This shift is good for the Visual Basic developer since much of the performance issues in Visual Basic arose around the cost of the COM interface.

Elementary geometry management via the Forms designer

edit

One of the true banes of a Visual Basic developer's life has always been writing resize code. Whilst the WinForms paradigm leaves a lot to be desired in the geometry management department in the face of toolkits like Qt and GTK+, at least the developer can anchor widgets on forms instead of having to write reams of code in OnResize handlers.

Option Explicit by default

edit

In Visual Basic .NET, Option Explicit is on by default.

References

edit

View original on Wikipedia | Back | FazBrowse Home