Q Basic Programming Language

QBasic
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QBasic
Appeared in 1991 - 2000
Developer Microsoft Corporation
Influenced by QuickBASIC, GW-BASIC
OS MS-DOS, Windows 95, Windows 98, Windows Me, PC-DOS, OS/2, eComStation
License MS-EULA
Website www.microsoft.com
QBasic is an IDE and interpreter for a variant of the BASIC programming language which is based on QuickBasic. Code entered into the IDE is compiled to an intermediate form, and this intermediate form is immediately interpreted on demand within the IDE.[1] It can run under nearly all versions of DOS and Windows, or through DOSBox/DOSEMU, on Linux and FreeBSD.[2] For its time, QBasic provided a state-of-the-art IDE, including a debugger with features such as on-the-fly expression evaluation and code modification that were still relatively unusual more than ten years later.[citation needed]

Like QuickBASIC, but unlike earlier versions of Microsoft BASIC, QBasic is a structured programming language, supporting constructs such as subroutines and while loops.[3][4] Line numbers, a concept often associated with BASIC, are supported for compatibility, but are not considered good form, having been replaced by descriptive line labels.[1] QBasic has limited support for user-defined data types (structures), and several primitive types used to contain strings of text or numeric data.[5][6]

Contents [hide]
1 History
2 Examples
2.1 "Hello, World!"
2.2 Simple game
3 Easter egg
4 References
5 See also
6 External links



[edit] History
QBasic was intended as a replacement for GW-BASIC. It was based on the earlier QuickBASIC 4.5 compiler but without QuickBASIC's compiler and linker elements. Version 1.0 was shipped together with MS-DOS 5.0 and higher, as well as Windows 95, Windows NT 3.x, and Windows NT 4.0. IBM recompiled QBasic and included it in PC-DOS 5.x, as well as OS/2 2.0 onwards.[7] eComStation, descended from OS/2 code, includes QBasic 1.0. QBasic 1.1 is included with MS-DOS 6.x, and, without EDIT, in Windows 95, Windows 98 and Windows Me. Starting with Windows 2000, Microsoft no longer includes QBasic with their operating systems.[8] (Although, some localized versions of Windows 2000 and Windows XP still have it.)

QBasic (as well as the built-in MS-DOS Editor) is backward compatible with DOS releases prior to 5.0 (down to at least DOS 3.20). However, if used on any 8088/8086 computers, or on some 80286 computers, the QBasic program may run very slowly, or perhaps not at all, due to its memory size. Until MS-DOS 7, MS-DOS Editor required QBasic. The "edit.com" program simply started QBasic in editor mode only.


[edit] Examples
QBasic came complete with four pre-written example programs. These were "Nibbles" (a variant of the Snake game), "Gorillas", an explosive-banana throwing game derived from Artillery game first produced on the Tektronix 4051 and later HP 2647, "MONEY MANAGER", a personal finance manager and "RemLine", a GW-BASIC code line number removing program.[1]


[edit] "Hello, World!"
PRINT "Hello, World!"

[edit] Simple game
This program challenges the user to guess a randomly selected number within the 1-10 range, without offering the usual hints of "higher"/"lower":

CLS
PRINT "Guess My Number"
INPUT "Would you like to play"; choice$ 'An input statement, that takes what the user inputs...
choice$ = UCASE$(choice$) ' makes the input completely uppercase (fkld ---> FKLD)
IF choice$ <> "YES" AND choice$ <> "Y" THEN ' and decides whether or not they want to play:
END
END IF
guesses% = 5 ' Set up number of guess remaining
RANDOMIZE TIMER ' Sets up the random number generator
target% = INT(RND * 10) + 1
WHILE guesses% > 0
INPUT "Guess a number: ", guess% ' Takes user input (the guess)
IF guess% = target% THEN ' Determines if the guess was correct
PRINT "You win!"
END
ELSE
guesses% = guesses% - 1
PRINT "Sorry, please try again. You have only ";guesses%;" times"
END IF
WEND

PRINT "You ran out of guesses, the number was "; target%
END

[edit] Easter egg
QBasic has a little known easter egg. To see it, press and hold Left CTRL+Left SHIFT+Left ALT and Right CTRL+Right SHIFT+Right ALT simultaneously after running QBasic at the DOS prompt but before the title screen loads: this lists The Team of programmers.[7] Note that on modern computers, it is much too fast to perform. It is best done on an old PC (preferably one with a working Turbo button, with the switch on to slow the CPU to 4.77 MHz) or in an emulator like Bochs or DOSBox which can be slowed down.


[edit] References
^ a b c "Differences Between GW-BASIC and QBasic". 2003-05-12. http://support.microsoft.com/kb/73084. Retrieved on 2008-06-28.
^ "HOWTO Play With Your Old QBasic Programs on Linux". 2007-03-31. http://penguinpetes.com/b2evo/index.php?title=howto_play_with_your_old_qbasic_programs. Retrieved on 2008-06-28.
^ "QBASIC Manual: SUB...END SUB Statement QuickSCREEN". http://www.qbasicnews.com/qboho/qcksub.shtml. Retrieved on 2008-06-28.
^ "QBASIC Manual: WHILE...WEND Statement QuickSCREEN". http://www.qbasicnews.com/qboho/qckwend.shtml. Retrieved on 2008-06-28.
^ "QBASIC Manual: TYPE Statement QuickSCREEN". http://www.qbasicnews.com/qboho/qcktype.shtml. Retrieved on 2008-06-28.
^ "QBASIC Manual: Limits - Names, Strings, and Numbers". http://www.qbasicnews.com/qboho/qckadvr@l8207.shtml. Retrieved on 2008-06-28.
^ a b "Microsoft BASIC version information". http://www.emsps.com/oldtools/msbasv.htm#qbasic. Retrieved on 2008-06-12.
^ "QBasic Missing from Windows 2000". 2007-03-01. http://support.microsoft.com/kb/258265. Retrieved on 2008-06-12.

[edit] See also
Wikibooks has a book on the topic of
QBasic
FreeBASIC
True Basic
Visual Basic
PowerBASIC
PureBasic
QB64

[edit] External links
Download QBASIC 1.1 from Microsoft (included in the "Old MS-DOS Utilities" part of Windows 95 CD-ROM Extras)
QB Express - Online magazine about QBasic programming
The QBasic Station - Created in 1997 by Jack Thomson, it is one of the oldest, but still active, QBasic sites on the web.