QBASIC - Statements
BEEP, BLOAD, BSAVE, CALL, CHAIN, CHDIR, CIRCLE, CLEAR, CLOSE, CLS, COLOR, COM, COMMON, CONST, DATA, DATE$, DECLARE, DEF, DEFDBL, DEFINT, DEFLNG, DEFSNG, DEFSTR, DIM, DO, DRAW, END, ENVIRON, ERASE, ERROR, EXIT, FIELD, FILES, FOR, FUNCTION, GET, GOSUB, GOTO, IF, INPUT, IOCTL, KEY, KILL, LET, LINE, LINE INPUT, LOCATE, LOCK, LPRINT, LSET, MID$, MKDIR, NAME, ON, OPEN, OPTION, OUT, PAINT, PALETTE, PCOPY, PEN, PLAY, POKE, PRESET, PRINT, PSET, PUT, RANDOMIZE, READ, REDIM, REM, RESET, RESTORE, RESUME, RETURN, RMDIR, RSET, RUN, SCREEN, SEEK, SELECT CASE, SHARED, SHELL, SLEEP, SOUND, STATIC, STOP, STRIG, SUB, SWAP, SYSTEM, TIME$, TROFF, TRON, TYPE, UNLOCK, VIEW, WAIT, WHILE, WIDTH, WINDOW, WRITE
Program
CALL
CHAIN
DECLARE
END
OPTION
REM
RUN
STOP
 
Event
ON
SLEEP
WAIT
 
Structure
DO
ERROR
EXIT
FOR
FUNCTION
GOSUB
GOTO
IF
RESUME
RETURN
SELECT CASE
SUB
WHILE
Data
CLEAR
COMMON
CONST
DATA
DEFDBL
DEFINT
DEFLNG
DEFSNG
DEFSTR
DIM
ERASE
INPUT
LET
MID$
RANDOMIZE
READ
REDIM
RESTORE
SHARED
SWAP
STATIC
TYPE
Pen
PEN
Joystick
STRIG
Keyboard
INPUT
KEY
LINE INPUT
 
Screen
CLS
COLOR
LOCATE
PALETTE
PCOPY
PRINT
SCREEN
VIEW
WIDTH
WINDOW
Printer
LPRINT
WIDTH
Graphics
CIRCLE
DRAW
GET
LINE
PAINT
PRESET
PSET
PUT
 
Sound
BEEP
PLAY
SOUND
 
Memory
BLOAD
BSAVE
CLEAR
DEF
DEF SEG
POKE
File
CLOSE
KILL
NAME
OPEN
RESET
Sequential file
INPUT
LINE INPUT
PRINT
WRITE
Random file
FIELD
GET
LOCK
LSET
PUT
RSET
SEEK
UNLOCK
Binary file
BLOAD
BSAVE
Directory
CHDIR
MKDIR
RMDIR
 
System
COM
ENVIRON
IOCTL
OUT
SHELL
SYSTEM
 
Date & Time
DATE$
TIME$
 
Debug
TROFF
TRON
 
BEEP
Sounds the speaker at 800 Hz for 1/4 second.
PRINT CHR$(7) also beeps
 
CIRCLE
>SCREEN 1: CIRCLE
 
CLOSE
Close an open file
>OPEN
 
DATA
>maskinkode: array
 
DEF
 
DEF SEG
Sets the current segment address.
DEF SEG [=address]
address    A segment address used by BLOAD, BSAVE, CALL ABSOLUTE, PEEK, or POKE
- a value in the range 0 - 65535.
If address is omitted, DEF SEG resets the current segment address to the default data segment.


Example:

DEF SEG = 0
Status% = PEEK(&H417) 
POKE &H417, (Status% XOR &H40)
DEF SEG
 
  
Read keyboard status.
Change Caps Lock state, bit 6.
Reset segment address.


>maskinkode: array

 
DIM
DIM declares an array or specifies a data type for a nonarray variable.
>REDIM, $DYNAMIC, $STATIC
DIM [SHARED] variable[(subscripts)] [AS type][, variable[(subscripts)] [AS type]]...
SHARED   Specifies that variables are shared with all SUB or FUNCTION procedures in the module.
subscripts Dimensions of the array, expressed as follows:
[lower TO] upper [, [lower TO] upper]...
lower   The lower bound of the array's subscripts.
The default lower bound is zero.
upper The upper bound.

>OPTION BASE
AS type Declares the data type of the array or variable:
INTEGER   A 16-bit signed integer variable
LONG A 32-bit signed integer variable
SINGLE A single-precision 32-bit floating-point variable
DOUBLE A double-precision 64-bit floating-point variable
STRING * n% A fixed-length string variable n% bytes long
STRING A variable-length string variable
  
DIM i%
DIM i AS INTEGER
DIM s AS STRING * 20
DIM a(4) AS SINGLE    '5 numbers (0 to 4)
 
DRAW
> SCREEN 1: DRAW
 
GET
>GET [File I/O]
>GET [Graphics]
 
IF...THEN...ELSE
IF condition THEN statements [ELSE statements]
 
IF condition THEN
   statements
[ELSEIF condition THEN
   statements]...
[ELSE
   statements]
END IF
 
KEY
>KEY [Assignment]
>KEY [Event Trapping]
 
LINE (Graphics)
> SCREEN 1: LINE
 
LOCATE
> SCREEN 0: LOCATE (show/hide/define cursor)
 
LPRINT
> Printer: LPRINT
> PRINT
 
MID$
The MID$ statement replaces part of a string variable with another string.
MID$(stringvariable$,start%[,length%])=stringexpression$
stringvariable$    The string variable being modified.
start% The position of the first character in the substring being replaced.
length% The number of characters in the substring. If the length is omitted, MID$ replaces all characters to the right of the start position.
stringexpression$ The replacement string. It can be any string expression.
Ex:
Text$ = "Paris, France"
PRINT Text$
MID$(Text$, 8) = "Texas "
PRINT Text$		  
Paris, France
 
Paris, Texas

>Function: MID$()

 
PAINT
> SCREEN 1: PAINT
 
PALETTE
> SCREEN 1: PALETTE
 
PLAY
> Sound: PLAY
> SOUND
> PLAY (Event Trapping)
 
POKE
> DEF SEG
> SCREEN 0: POKE (attributes and chars)
> PEEK()
 
PRESET
> PSET
> SCREEN 1: PRESET
 
PSET
> PRESET
> SCREEN 1: PSET
 
PUT
>PUT (File I/O)
>PUT (Graphics)
>GET
 
RANDOMIZE [seed]
Benytter 'seed' til at danne en ny start på den sekvens af 'tilfældige' tal, som RND() returnerer.
Med en fast seed-værdi kan man sikre, at den tilfældige sekvens altid er den samme:
RANDOMIZE 124
FOR i = 1 TO 4
  PRINT RND
NEXT
 .2441675
.214439
.6458486
.7624476
Hvis talsekvensen skal være 'rigtig tilfældig' benyttes
RANDOMIZE TIMER
der benytter maskines aktuelle tid som seed. 
 
REDIM
REDIM declares or resizes a dynamic array, erasing any previous values.
REDIM [SHARED] variable[(subscripts)] [AS type][, variable[(subscripts)] [AS type]]...
>DIM
 
SOUND
> Sound: SOUND
> PLAY
 
SYSTEM
Lukker alle åbne filer og returnere til operativsystemet (DOS)
 
VIEW
Definerer et område af en grafik-skærm ("viewport") - grafik (men ikke tekst) bliver begrænset til dette område.
VIEW Uden parametre nulstiller en defineret Viewport - så hele skærmen benyttes til grafik.
Grafikkoordinater er relative til en defineret Viewport - men:
VIEW SCREEN ... benytter absolutte koordinater.
CLS rydder kun det indre af en Viewport.
  
VIEW [[SCREEN] (x1!,y1!)-(x2!,y2!) [,[color%] [,border%]]]
 
SCREEN                 Specifies that coordinates are relative to the
                       screen rather than the viewport.
(x1!,y1!)-(x2!,y2!)    The coordinates of diagonally opposite corners
                       of the viewport.
color%                 A color attribute that sets the viewport fill
                       color. Depends on Screen mode.
border%                A color attribute that sets the viewport border
                       color. Depends on Screen mode.

 
Følgende to rutiner (uden og med SCREEN) giver samme resultat (bemærk parametrene til CIRCLE):

SCREEN 1
VIEW (80, 80)-(160, 120), , 1
LOCATE 13, 13: PRINT "A viewport";
CIRCLE (25, 20), 30
SCREEN 1
VIEW SCREEN (80, 80)-(160, 120), , 1
LOCATE 13, 13: PRINT "A viewport";
CIRCLE (105, 100), 30
 et udsnit af skærmen:
view1.gif (1722 bytes)		 
SCREEN 1
VIEW (80, 80)-(160, 120), 2, 1
LOCATE 13, 13: PRINT "A viewport";
CIRCLE (25, 20), 30
 view2.gif (1904 bytes)
 
WHILE...WEND
WHILE
  'statements
WEND
 
Wait for any key: 
WHILE Inkey$="": WEND
 
WIDTH
> SCREEN