Commands

This page lists the bunnyBASIC statements and built-in functions that are implemented in the current browser runtime.

Program statements

PRINT

Print one or more expressions.

10 PRINT "score", 42, TRUE

Arguments are comma-separated, and the runtime prints them with spaces between values.

Assignment

Assign an expression to a variable:

10 $NAME = "bunny"
20 $COUNT = 12

IF / ELSE / END IF

Multi-line conditional blocks:

10 IF $COUNT > 10
20   PRINT "large"
30 ELSE
40   PRINT "small"
50 END IF

FOR / END FOR

Ascending loop with optional STEP:

10 FOR $I = 0 TO 10 STEP 2
20   PRINT $I
30 END FOR

The current runtime is designed around upward iteration. Write FOR loops from lower values to higher values.

WHILE / END WHILE

Standard condition-controlled loop:

10 $N = 0
20 WHILE $N < 3
30   PRINT $N
40   $N = $N + 1
50 END WHILE

Functions

FUNCTION / END FUNCTION

Define a function. Parameters are variables, so they use $.

10 PRINT DOUBLE(21)
20 FUNCTION DOUBLE($N)
30   RETURN $N + $N
40 END FUNCTION

FUN is also accepted as a shorter spelling, but the full form is the clearest one to document and use.

GLOBALS

Inside a function, variables are local by default. Add GLOBALS (...) when you need to touch top-level variables.

10 $COUNT = 0
20 CALL BUMP()
30 PRINT $COUNT
40 FUNCTION BUMP() GLOBALS ($COUNT)
50   $COUNT = $COUNT + 1
60 END FUNCTION

RETURN

Return a value from a function:

10 PRINT ADD(2, 3)
20 FUNCTION ADD($A, $B)
30   RETURN $A + $B
40 END FUNCTION

Function calls in expressions

Call a function anywhere an expression is allowed:

10 PRINT SIN(DEG(90.0))

CALL

Use CALL when you want to invoke a function as a statement and ignore its return value:

10 CALL SHOW("hello")
20 FUNCTION SHOW($TEXT)
30   PRINT $TEXT
40 END FUNCTION

Timers and delays

CALL ... AFTER

Schedule a user-defined function once:

10 CALL HELLO("timer") AFTER 500 MS ID 1
20 DELAY 1 SEC
30 FUNCTION HELLO($NAME)
40   PRINT "hello", $NAME
50 END FUNCTION

CALL ... EVERY

Schedule a repeating timer:

10 CALL TICK() EVERY 1 SEC ID 1
20 DELAY 3 SEC
30 CANCEL TIMER 1
40 FUNCTION TICK()
50   PRINT "tick", SECOND()
60 END FUNCTION

DELAY

Pause program execution for an integer amount of time:

10 PRINT "wait"
20 DELAY 250 MS
30 PRINT "done"

Units:

MS
SEC

CANCEL TIMER

Cancel a timer created with ID:

10 CANCEL TIMER 1

Arrays

Array literal

Create arrays directly:

10 $WORDS = ["bunny", "basic"]

Index read and write

10 $NUMS = [10, 20, 30]
20 PRINT $NUMS[1]
30 $NUMS[1] = 99

Push and unshift

10 $NUMS = [1, 2]
20 $NUMS[] = 3
30 $NUMS() = 0

Pop and shift as expressions

10 $NUMS = [1, 2, 3]
20 PRINT $NUMS[]
30 PRINT $NUMS()

Graphics statements

The immediate graphics API works on a 512 x 512 pixel canvas and expects integer arguments.

CLS

Clear the canvas and terminal:

10 CLS

PIXEL

Draw a single pixel:

10 PIXEL (100, 120), 12

LINE

Draw a line:

10 LINE (20, 20)-(200, 120), 10

CIRCLE

Draw a circle outline or rasterized circle with center, radius, and palette index:

10 CIRCLE (256, 256), 80, 12

PALETTE

Override a palette entry with RGB values from 0 to 255:

10 PALETTE 20, (255, 128, 0)
20 LINE (20, 20)-(180, 100), 20

DRAW

Render a shape expression:

10 $SHIP = <256.0, 256.0> + (48.0 * RECT())
20 DRAW $SHIP

REPL and file commands

These commands are intended for the terminal prompt, not for storing inside a numbered program.

RUN

Run the current stored program:

RUN

LIST

Show the numbered program listing:

LIST

PRETTY

Show a formatted version of the current program:

PRETTY

RENUM

Renumber the stored program. Default start is 10.

RENUM
RENUM 100

NEW

Clear the stored program:

NEW

DIR

List saved files:

DIR

SAVE / LOAD / RM

Persist a program in browser storage:

SAVE "demo.bas"
LOAD "demo.bas"
RM "demo.bas"

Filenames currently need to match this shape:

quoted
end in .bas
letters, digits, _, and -

Built-in functions

The following built-ins are available as expressions.

Function	Returns	Notes
`EXP(x)`	`DECIMAL`	`x` must be decimal
`LEN(arr)`	`INTEGER`	array length only
`RAND(n)`	`INTEGER`	random integer in `[0, n)`
`SIN(x)`	`DECIMAL`	decimal input
`COS(x)`	`DECIMAL`	decimal input
`INT(x)`	`INTEGER`	decimal to integer
`DECIMAL(x)`	`DECIMAL`	integer to decimal
`DEG(x)`	`DECIMAL`	degrees to radians
`RECT()`	`SHAPE`	unit rectangle
`CIRCLE()`	`SHAPE`	unit circle
`HOUR()`	`INTEGER`	current browser hour
`MINUTE()`	`INTEGER`	current browser minute
`SECOND()`	`INTEGER`	current browser second
`POP(arr)`	array element	removes last element
`SHIFT(arr)`	array element	removes first element
`GETPIXEL(x, y)`	`INTEGER`	palette index at pixel

Examples:

10 PRINT RAND(10)
20 PRINT SIN(DEG(90.0))
30 PRINT GETPIXEL(10, 10)