Module basic::__Chapter_2

Statements

Statements describe what the program does. The original Dartmouth BASIC was separated into a compiler and operating system with statements like GOTO and PRINT for the compiled language and commands like SAVE and LIST for controlling the system. 64K BASIC is a unique implementation where everything is compiled and executed by a virtual machine. There are no commands, everything is a statement.

Statements tend to be short and it's common to put multiple statements on a single line. Use a colon : to separate statements. This works in both direct and indirect modes.

FOR I = 1 TO 10 : PRINT I : NEXT I

Statement words can never be used in variable names. 64K BASIC will insert spaces to help you when you accidentally include a word in a variable name.

LET BONK = 1
10 LET B ON K = 1

Statements need to be properly formatted with the information they need. Angled brackets <> are used to indicate required items. Square brackets [] are used to indicate optional items. Ellipsis ... indicate items that may repeat. Vertical bars | separate mutually exclusive options. All letters and punctuation not in brackets are required.

Modules

CLEAR	CLEAR [...]
CLS	CLS
CONT	CONT
DATA	DATA <literal>[,<literal>...]
DEF	DEF FN<name>(<argument>[,<argument>...]) = <expression>
DEFTYPE	DEFINT/SNG/DBL/STR <range of letters>
DELETE	DELETE [<line number range>]
DIM	DIM <variable name>(<dimensions>)[,...]
END	END
ERASE	ERASE [<array variable>][,<array variable>...]
FOR	FOR <variable>=<x> TO <y> [STEP <z>]
GOSUB	GOSUB <line number>
GOTO	GOTO <line number>
IF	IF <expression> THEN <statements> [ELSE <statements>]
INPUT	INPUT [,]["<prompt string>";]<variable>[,<variable>...]
LET	[LET] <variable>=<expression>
LIST	LIST [<line number range>]
LOAD	LOAD <filename>
MID	[LET] MID$(<string>,n[,m])=<expression>
NEW	NEW
NEXT	NEXT [<variable>][,<variable>...]
ON	ON expression <GOTO|GOSUB> <line>[,<line>...]
PRINT	PRINT [<list of expressions>]
READ	READ <variable>[,<variable>...]
REM	REM [<anything>] or ' [<anything>]
RENUM	RENUM [<new number>][,<old number>][,<increment>]
RESTORE	RESTORE [<line number>]
RUN	RUN [<line number>|<filename>]
SAVE	SAVE <filename>
STOP	STOP
SWAP	SWAP <variable>,<variable>
TRON	TRON | TROFF
WHILE	WHILE <expression> : WEND