Standard Snap Blocks Reference

The Snap Manual details many of the operators provided in the language but is not comprehensive. The following reference is intended to provide a quick guide to every standard operator in the native set as well as a few of the libraries. The course library is documented in Drama Library Blocks Reference.

Key to Block Descriptions

Standard library

Includes the primitive blocks always available in Snap!.

Tools library

These blocks are available once Import Tools is run from the File menu.

Finch library

The blocks in the BirdBrain Finch-Chrome library, which can found in the Snap sketch loaded by the Chrome Finch Connection App.

Key to Block Arguments

The argument notation is idiosyncratic, but follows this convention:

Symbol	Data Type
#	numeric value
<>	Boolean value
""	string
[]	list
*	general value (text or string)
&	name of variable, sprite, operation, etc.
()	procedure
[%]	color (selected from color picker)
...	variable number of arguments

Key to Block Shapes

Shape	Category	Properties
C-shaped	special form	accepts one or more procedures within the body
oval	reporter	returns a value
tabbed	command	called for side-effects (no return value)
hexagon	predicate	returns a Boolean value
hat	entry point	starts a thread of execution, i.e., a script
cap	exit point	ends a procedure or thread

Table of Blocks

Library	Palette	Color	Shape	Name	Arguments	Notes
Standard	Control	gold	C-shaped	forever
Standard	Control	gold	C-shaped	if <>	Boolean-value
Standard	Control	gold	C-shaped	if <> else	Boolean-value
Standard	Control	gold	C-shaped	repeat #	iteration-count
Standard	Control	gold	C-shaped	repeat until <>	Boolean-value
Standard	Control	gray	C-shaped	warp		runs a script in turbo mode
Standard	Control	gold	cap	delete this clone
Standard	Control	gold	cap	report *	value
Standard	Control	gold	cap	stop &	script-selection
Standard	Control	gold	hat	when & key pressed	key
Standard	Control	gold	hat	when <>	Boolean-value
Standard	Control	gold	hat	when flag clicked
Standard	Control	gold	hat	when I am &	condition-name
Standard	Control	gold	hat	when I receive &	message-name
Standard	Control	gold	hat	when I start as a clone
Standard	Control	gold	oval	call ()	reporter-function
Standard	Control	gold	oval	call () w/continuation	command-function
Standard	Control	gold	oval	message		reports the most recently broadcast message
Standard	Control	gold	tabbed	broadcast &	message-name
Standard	Control	gold	tabbed	broadcast & and wait	message-name
Standard	Control	gold	tabbed	create a clone of &	sprite
Standard	Control	gold	tabbed	launch ()	command-function
Standard	Control	gold	tabbed	pause all
Standard	Control	gold	tabbed	run ()	command-function
Standard	Control	gold	tabbed	run () w/continuation	command-function
Standard	Control	gold	tabbed	stop &	script-selection
Standard	Control	gold	tabbed	wait # seconds	seconds
Standard	Control	gold	tabbed	wait until <>	Boolean-value
Standard	Looks	purple	oval	costume		returns the current sprite costume number
Standard	Looks	purple	oval	size		returns the current size percentage
Standard	Looks	purple	tabbed	change & effect by #	effect-name, value
Standard	Looks	purple	tabbed	change size by #	value
Standard	Looks	purple	tabbed	clear graphic effects
Standard	Looks	purple	tabbed	go back # layers	value
Standard	Looks	purple	tabbed	go to front
Standard	Looks	purple	tabbed	hide
Standard	Looks	purple	tabbed	next costume
Standard	Looks	purple	tabbed	say “”	string	places a speech balloon near a sprite
Standard	Looks	purple	tabbed	say “” for # secs	string, duration	places a speech balloon near a sprite
Standard	Looks	purple	tabbed	set & effect to #	effect-name, value
Standard	Looks	purple	tabbed	set size to # %	percentage-value
Standard	Looks	purple	tabbed	show
Standard	Looks	purple	tabbed	switch to costume &	costume-name
Standard	Looks	purple	tabbed	think “”	string	places a thought bubble near a sprite
Standard	Looks	purple	tabbed	think “” for # secs	string, duration	places a thought bubble near a sprite
Standard	Motion	blue	oval	direction
Standard	Motion	blue	oval	x position
Standard	Motion	blue	oval	y position
Standard	Motion	blue	tabbed	change x by #	x
Standard	Motion	blue	tabbed	change y by #	y
Standard	Motion	blue	tabbed	glide # secs to x: # y: #	duration, x, y
Standard	Motion	blue	tabbed	go to &	target-name	a sprite name or mouse-pointer
Standard	Motion	blue	tabbed	go to x: # y: #	x, y
Standard	Motion	blue	tabbed	if on edge, bounce
Standard	Motion	blue	tabbed	move # steps	step-count
Standard	Motion	blue	tabbed	point in direction #	angle
Standard	Motion	blue	tabbed	point towards &	target-name	a sprite name or mouse-pointer
Standard	Motion	blue	tabbed	set x to #	x
Standard	Motion	blue	tabbed	set y to #	y
Standard	Motion	blue	tabbed	turn CCW # degrees	angle
Standard	Motion	blue	tabbed	turn CW # degrees	angle
Standard	Operators	green	hexagon	# < #	number, number
Standard	Operators	green	hexagon	# < #	number, number
Standard	Operators	green	hexagon	# = #	number, number
Standard	Operators	green	hexagon	<> and <>	Boolean-value, Boolean-value
Standard	Operators	green	hexagon	<> or <>	Boolean-value, Boolean-value
Standard	Operators	green	hexagon	false
Standard	Operators	green	hexagon	is * a &?	value, type-identifier
Standard	Operators	green	hexagon	is * identical to * ?	value, value
Standard	Operators	green	hexagon	not <>	Boolean-value
Standard	Operators	green	hexagon	true
Standard	Operators	green	oval	& of #	operator-name, number	example operators are abs, sqrt, acose...
Standard	Operators	green	oval	# - #	number, number
Standard	Operators	green	oval	# * #	number, number
Standard	Operators	green	oval	# / #	number, number
Standard	Operators	green	oval	# + #	number, number
Standard	Operators	green	oval	# mod #	number, number
Standard	Operators	green	oval	JavaScript function ( “”...){“”...}	args, code
Standard	Operators	green	oval	join “” “”...	string, string...
Standard	Operators	green	oval	length of “”	string
Standard	Operators	green	oval	letter # of “”	index-value, string
Standard	Operators	green	oval	pick random # to #	low-value, high-value
Standard	Operators	green	oval	round #	number
Standard	Operators	green	oval	split “” by &	string, character
Standard	Operators	green	oval	unicode # as letter	ordinal-value
Standard	Operators	green	oval	unicode of &	character
Standard	Operators	gray	predicate-ring			passes a procedure as a value
Standard	Operators	gray	reporter-ring			passes a procedure as a value
Standard	Operators	gray	command-ring			passes a procedure as a value
Standard	Pen	aqua	tabbed	change pen color by #	number	there are 200 pen colors
Standard	Pen	aqua	tabbed	change pen shade by #	number	the pen shade goes from 0 to 100
Standard	Pen	aqua	tabbed	change pen size by #	pixel-value
Standard	Pen	aqua	tabbed	clear
Standard	Pen	aqua	tabbed	fill
Standard	Pen	aqua	tabbed	pen down
Standard	Pen	aqua	tabbed	pen up
Standard	Pen	aqua	tabbed	set pen color to [%]	color-selection
Standard	Pen	aqua	tabbed	set pen color to #	number
Standard	Pen	aqua	tabbed	set pen shade to #	number
Standard	Pen	aqua	tabbed	set pen size to #	pixel-value
Standard	Pen	aqua	tabbed	stamp		stamp a print of the costume image
Standard	Sensing	cyan	hexagon	color [%] is touching [%] ?	color-selection, color-selection
Standard	Sensing	cyan	hexagon	key & pressed?	key
Standard	Sensing	cyan	hexagon	mouse down?
Standard	Sensing	cyan	hexagon	touching [%]?	color-selection
Standard	Sensing	cyan	hexagon	touching &?	sprite-name
Standard	Sensing	cyan	hexagon	turbo mode?
Standard	Sensing	cyan	oval	& of &?	property-name, sprite-name	property examples: x-position, costume name
Standard	Sensing	cyan	oval	answer
Standard	Sensing	cyan	oval	current &	time-value-name	e.g. year, month, day; “time in milliseconds” is epoch time
Standard	Sensing	cyan	oval	distance to &	sprite-name
Standard	Sensing	cyan	oval	http:// “”	url
Standard	Sensing	cyan	oval	mouse x
Standard	Sensing	cyan	oval	mouse y
Standard	Sensing	cyan	oval	timer
Standard	Sensing	cyan	tabbed	ask “” and wait	string
Standard	Sensing	cyan	tabbed	reset timer
Standard	Sensing	cyan	tabbed	set turbo mode to <>	Boolean-value
Standard	Sound	magenta	oval	tempo
Standard	Sound	magenta	tabbed	change tempo by #	bpm-value
Standard	Sound	magenta	tabbed	play note # for # beats	note-number, beat-duration
Standard	Sound	magenta	tabbed	play sound &	sound-name
Standard	Sound	magenta	tabbed	play sound & until done	sound-name
Standard	Sound	magenta	tabbed	rest for # beats	beats
Standard	Sound	magenta	tabbed	set tempo to # bpm	bpm-value
Standard	Sound	magenta	tabbed	stop all sounds
Standard	Variables	orange	tabbed	change & by #	variable-name, number
Standard	Variables	orange	tabbed	hide-variable &	variable-name	hides the watcher for the variable
Standard	Variables	orange	tabbed	set & to *	variable-name, value
Standard	Variables	orange	tabbed	show variable &	variable-name	makes a watcher visible in the stage
Standard	Variables	gray	tabbed	script variables &...	variable-name...	declare script-local variables in the current scope
Standard	Variables	red	hexagon	[] contains *	list, value
Standard	Variables	red	oval	* in front of []	value, list	returns a new list with the value prepended (cons)
Standard	Variables	red	oval	all but first of []	list
Standard	Variables	red	oval	item # of []	index-value, list
Standard	Variables	red	oval	length of []	list
Standard	Variables	red	oval	list *...	value	note: list with no values returns an empty list
Standard	Variables	red	tabbed	add * to []	value, list	appends an item to the end of the list
Standard	Variables	red	tabbed	delete # of []	index-value, list
Standard	Variables	red	tabbed	insert * at # of []	value, index-value, list
Standard	Variables	red	tabbed	replace item # of [] with *	index-value, list, value
Tools	Control	gold	C-shaped	catch & *	variable-name, value
Tools	Control	gold	C-shaped	for & = # to #	variable-name, lower-value, upper-value
Tools	Control	gold	C-shaped	if <> do and pause all	Boolean-value
Tools	Control	gold	C-shaped	tell & to	sprite-name
Tools	Control	gold	oval	ask & for ()	sprite-name, reporter-function
Tools	Control	gold	oval	catch &	variable-name	defines a scope for throw <>
Tools	Control	gold	oval	if <> then * else *	Boolean-value, value, value
Tools	Control	gold	tabbed	ignore *	value
Tools	Control	gold	tabbed	throw &	variable-name
Tools	Control	gold	tabbed	throw & *	variable-name, value
Tools	Operators	green	oval	join words “”	string
Tools	Operators	green	oval	list -> sentence []	list
Tools	Operators	green	oval	list -> word []	list
Tools	Operators	green	oval	sentence -> list “”	string
Tools	Operators	green	oval	word -> list “”	string
Tools	Pen	aqua	tabbed	label “” of size #	string, size-value
Tools	Variables	orange	C-shaped	for each & of []	variable-name, list
Tools	Variables	orange	hexagon	empty? []	list
Tools	Variables	orange	oval	combine with () items of []	reporter-function, list
Tools	Variables	orange	oval	keep items such that () from []	Boolean-function, list
Tools	Variables	orange	oval	map () over []	reporter-function, list
Finch	Looks	purple	tabbed	Finch LED R: # G: # B: #	red, green, blue	colors range from 0 to 100
Finch	Motion	blue	tabbed	Move Finch Left: # Right: #	left-speed, right-speed	speeds range from -100 to 100
Finch	Motion	blue	tabbed	Stop Finch
Finch	Sensing	cyan	hexagon	Finch Left Obstacle
Finch	Sensing	cyan	hexagon	Finch Right Obstacle
Finch	Sensing	cyan	oval	Finch Accelerations		returns a list with [X,Y,Z] acceleration components
Finch	Sensing	cyan	oval	Finch Left Light Sensor
Finch	Sensing	cyan	oval	Finch Light Sensors
Finch	Sensing	cyan	oval	Finch Obstacles		returns list of two Booleans
Finch	Sensing	cyan	oval	Finch Orientation		returns an orientation name string, e.g. “level”, “left wing down”, etc.
Finch	Sensing	cyan	oval	Finch Right Light Sensor
Finch	Sensing	cyan	oval	Finch Temperature Celsius
Finch	Sensing	cyan	oval	Finch Temperature Fahrenheit
Finch	Sensing	cyan	oval	Finch X Acceleration
Finch	Sensing	cyan	oval	Finch Y Acceleration
Finch	Sensing	cyan	oval	Finch Z Acceleration		ranges from 1 (right-side up) to -1 (upside-down)
Finch	Sound	magenta	tabbed	Finch Buzz+Wait # Hz # ms	Hz-value, msec-duration
Finch	Sound	magenta	tabbed	Finch Buzzer # Hz # ms	Hz-value, msec-duration
Finch	Sound	magenta	tabbed	Say This “”	string	performs speech synthesis on host computer