Functions

QBASIC - Functions

ABS, ASC, ATN, CDBL, CHR$, CINT, CLNG, COS, CSNG, CSRLIN, CVD, CVDMBF, CVI, CVL, CVS, CVSMBF, DATE$, ENVIRON$, EOF, ERDEV, ERDEV$, ERL, ERR, EXP, FILEATTR, FIX, FRE, FREEFILE, HEX$, INKEY$, INP, INPUT$, INSTR, INT, IOCTL$, LBOUND, LCASE$, LEFT$, LEN, LOC, LOF, LOG, LPOS, LTRIM$, MID$, MKDMBF$, MKI$, MKL$, MKS$, MKSMBF$, OCT$, PEEK, PEN, PLAY, PMAP, POINT, POS, RIGHT$, RND, RTRIM$, SADD, SCREEN, SEEK, SETMEM, SGN, SIN, SPACE$, SPC, SQR, STICK, STR$, STRIG, STRING$, TAB, TAN, TIME$, TIMER, UBOUND, UCASE$, VAL, VARPTR, VARPTR$, VARSEG

String: INSTR
LCASE$
UCASE$
LEFT$
MID$
RIGHT$
LEN
LTRIM$
RTRIM$
SPACE$
STRING$

Conversion

Numeric: CDBL
CINT
CLNG
CSNG
CVD
CVI
CVL
CVS
CVDMBF
CVSMBF

Number > String: CHR$
HEX$; OCT$
STR$
MKD$
MKI$
MKL$
MKS$
MKDMBF$
MKSMBF$
String > Number: ASC
VAL

Mathematical: ABS
ATN
COS
EXP
FIX
INT
LOG
RND
SGN
SIN
SQR
TAN
Array: LBOUND
UBOUND

Input: INKEY$
INP
INPUT$; PEN
STICK
STRIG
Print: LPOS
SPC
TAB

Screen: CSRLIN
POS
SCREEN

Graphics: PMAP
POINT
Sound: PLAY
File: EOF
LOC
LOF
Error: ERDEV
ERDEV$
ERR
ERL

System: ENVIRON$
FRE
PEEK
POKE
IOCTL$
SETMEM
SADD
VARPTR
VARPTR$
VARSEG
Time: DATE$
TIME$
TIMER

ENVIRON$()

EOF()

ERDEV()

Returns an error code from the last device that generated a critical error.

The low byte of the value returned by ERDEV contains the DOS error code. The high byte contains device-attribute information.

ERDEV$()

Returns the name of the device that generated the error.

ERL()

ERR()

FILEATTR()

FRE()

Returns the amount (in bytes) of available or unused memory.
>SETMEM

FRE(numeric-expression)
FRE(stringexpression$)

numeric-expression

A value that specifies the type of memory FRE returns:

-1		The size of the largest array (nonstring) you can create
-2		The unused stack space
Any other number		The available string space

stringexpression$

Any string expression

FRE compacts the free string space into a single block, then returns the amount of available string space.

PRINT "Array Space", FRE(-1)
PRINT "Unused Stack Space", FRE(-2)
PRINT "String Space", FRE("")

PRINT "Far Heap", SETMEM(0)

Array Space        159708
Unused Stack Space 1050
String Space       31196

Far Heap           163824

FREEFILE

IOCTL$()

LBOUND()

LOC

LOF

LPOS

PEEK(n)

>DEF SEG, POKE

PEN

PLAY

PMAP

POINT

POS

SCREEN()

SETMEM()

Changes the amount of memory used by the far heap (where arrays are stored) and returns information about the far heap.
>FRE

SETMEM(numeric-expression&)

numeric-expression&

Specifies the number of bytes by which the far heap will increase or decrease; in addition, specifies the return value of the function:

Numeric Expression		Far Heap		Return Value
Negative 0 Positive		Decrease No change Increase		Maximum size of far heap Current size of far heap Maximum size of far heap

PRINT SETMEM(0)      '163824
PRINT SETMEM(-1024)  '162800

SEEK

STICK

STRIG

SPC()

>PRINT SPC()

TAB()

>PRINT TAB()

UBOUND