SLogo Basic Commands

Math Operations

Name	Description
SUM num1 num2	returns sum of num1 and num2
DIFFERENCE num1 num2	returns difference of num1 and num2
PRODUCT num1 num2	returns product of num1 and num2
QUOTIENT num1 num2	returns integer quotient of num1 and num2
REMAINDER num1 num2	returns integer remainder on dividing num1 by num2. The result is the same sign as num2
MINUS num	returns negative of num

Drawing Operations and Turtle Commands

Command	Description
FORWARD dist FD dist	moves the turtle forward by dist pixels
BACK dist BK dist	moves the turtle backwards by the amount specified
LEFT degrees LT degrees	turns the turtle counterclockwise by the specified angle
RIGHT degrees RT degrees	turns the turtle clockwise by the specified angle
SETXY xcor ycor	moves the turtle to an absolute screen position.
SETX xcor	moves the turtle horizontally to a new absolute horizontal coordinate
SETY ycor	moves the turtle vertically to a new absolute vertical coordinate.
HOME	moves the turtle to the center of the screen (0 0)
XCOR	returns the turtle's X coordinate
YCOR	returns the turtle's Y coordinate
HEADING	returns the turtle's heading in degrees
TOWARDS xcor ycor	returns a heading the turtle should be facing to point from its current position to the given position
SHOWTURTLE ST	makes the turtle visible
HIDETURTLE HT	makes the turtle invisible
CLEAN	clears the drawing area (the turtle's statistics do not reset)
CLEARSCREEN CS	erases the drawing area and sends the turtle to the home position (Like CLEAN and HOME)
PENDOWN PD	sets the pen's position to DOWN
PENUP PU	sets the pen's position to UP
PENDOWNP PENDOWN?	returns 1 (:TRUE) if the pen is down, 0 (:FALSE) if it's up.

Control Structures and Procedures

Command	Description
REPEAT numOrVar [ instructionlist ]	runs instructionlist numOrVar times
IF varOrCommand [ instructionlist ]	if varOrCommand is not 0, run instructionlist
TO sub_name [ instructionlist ]	defines a new subroutine (command) named subr_name. When invoked, the subroutine will execute the body of instructions included in the definition.

Boolean Operations

Command	Description
LESS? num1 num2	returns 1(:TRUE) if its first input is strictly less than its second, or 0 otherwise (:FALSE)
GREATER? num1 num2	returns 1 if its first input is strictly greater than its second, or 0 otherwise
EQUAL? thing1 thing2	returns 1 if the two inputs are equal, 0 otherwise
NOTEQUAL? thing1 thing2	returns 1 if the two inputs are not equal, 0 otherwise