FreeBASIC

Not to be confused withFree Basics.

FreeBASIC

Paradigm	Procedural,object-oriented
Designed by	Andre Victor
Developer	The FreeBASIC Development Team
First appeared	2004(2004)
Stable release	1.10.1 / December 25, 2023(2023-12-25)
Typing discipline	Static
OS	MS-DOS,FreeBSD,Linux,Microsoft Windows
License	GNU GPLv2+,Standard libraries licensed under the GNU LGPLv2+
Website	www.freebasic.net
Influenced by
QuickBASIC,C

FreeBASICis afree and open sourcemultiplatformcompilerandprogramming languagebased onBASIClicensed under theGNU GPLforMicrosoft Windows,protected-modeMS-DOS(DOS extender),Linux,FreeBSDandXbox.The Xbox version is no longer maintained.

According to its official website,FreeBASIC provides syntax compatibility withprogramsoriginally written inMicrosoft QuickBASIC(QB). Unlike QuickBASIC, however, FreeBASIC is a command line onlycompiler,unless users manually install an externalintegrated development environment(IDE) of their choice.

Compiler features

On itsbackend,FreeBASIC makes use ofGNU Binutilsin order to produce console andgraphical user interfaceapplications. FreeBASIC supports the linking and creation ofCstatic and dynamiclibrariesand has limited support forC++libraries. As a result, code compiled in FreeBASIC can be reused in most native development environments.

While not anoptimizing compiler,FreeBASIC can optionallytranscompileto C to compile with optimizations. FreeBASIC supportsinline assembly,multi-threading,and does not useautomatic garbage collection.

C style preprocessing,including multilinemacros,conditional compiling and file inclusion, is supported. The preprocessor also has access to symbol information and compiler settings, such as thelanguage dialect.

Syntax

Initially, FreeBASIC emulated Microsoft QuickBASIC syntax as closely as possible. Beyond that, the language has continued its evolution. As a result, FreeBASIC combines several language dialects for maximum level of compatibility with QuickBASIC and full access to modern features.New features include support for concepts such asobjects,operator overloading,function overloading,namespacesand others.

Newlinecharacters indicate the termination of programming statements. A programming statement can be distributed on multiple consecutive lines by using the underscoreline continuation char(_), whereas multiple statements may be written on a single line by separating each statement with acolon(:).

Blockcomments,as well as end-of-line remarks are supported. Full line comments are made with anapostrophe',while blocks of commented code begin with/'and end with'/.

FreeBASIC is not case-sensitive.

Graphics library

FreeBASIC provides built-in, QuickBASIC compatible graphics support through FBgfx, which is automatically included into programs that make a call to theSCREENcommand. Its backend defaults toOpenGLonLinuxandDirectXonMicrosoft Windows.This abstraction makes FBgfx graphics code cross-platform compatible. However, FBgfx is not hardware accelerated.

Users familiar with external graphics utilities such as OpenGL or the Windows API can use them without interfering with the built-in graphics library.

Language dialects

As FreeBASIC has evolved, changes have been made that required breaking older-styled syntax. In order to continue supporting programs written using the older syntax, FreeBASIC now supports the following dialects:

• The default dialect (-lang fbas acommand-line argument) supports all new compiler features and disallows archaic syntax.
• The FB-lite dialect (-lang fblite) permits use of most new, non-object-oriented features in addition to older-style programming. Implicit variables, suffixes,GOSUB/RETURN,numeric labelsand other features are allowed in this dialect.
• The QB dialect (-lang qb) attempts to replicate QuickBASIC behavior and is able to compile many QuickBASIC programs without modification.

Example code

Standard programs, such as the"Hello, World!" programare done just as they were in QuickBASIC.

Print"Hello, World!"

sleep:end'Comment, prevents the program window from closing instantly

FreeBASIC adds to this with support forobject-orientedfeatures such asmethods,constructors,dynamic memory allocation,propertiesand temporary allocation.

TypeVector
Private:
xAsInteger
yAsInteger
Public:
DeclareConstructor(nXAsInteger=0,nYAsInteger=0)
DeclarePropertygetXAsInteger
DeclarePropertygetYAsInteger
EndType

ConstructorVector(nXAsInteger,nYAsInteger)
x=nX
y=nY
EndConstructor

PropertyVector.getXAsInteger
Returnx
EndProperty

PropertyVector.getYAsInteger
Returny
EndProperty

DimAsVectorPtrplayer=NewVector()

*player=Type<Vector>(100,100)
Printplayer->getX
Printplayer->getY

Deleteplayer

Sleep'Prevents the program window from closing instantly

In both cases, the language is well suited for learning purposes.

External links

• Official website
• FreeBASIConGitHub
• FreeBASIConSourceForge

IDEs

• WinFBE- Modern FreeBASIC Editor for Windows
• VisualFBEditor- Cross-platform graphical IDE
• fbide.freebasic.net— FBIDE Integrated Development Environment for freeBASIC
• FBEdit (current)— FBEdit source code editor for FreeBASIC, version 1.0.7.6c
• FBEdit source code editor for freeBASIC (outdated version: 1.0.6.8)onSourceForge