Logo Programming Language Cheatsheet

Basic Commands

`FORWARD fd` or `FD fd`	Moves the turtle forward by `fd` units.
`BACK bk` or `BK bk`	Moves the turtle backward by `bk` units.
`RIGHT rt` or `RT rt`	Rotates the turtle clockwise by `rt` degrees.
`LEFT lt` or `LT lt`	Rotates the turtle counter-clockwise by `lt` degrees.
`PENUP` or `PU`	Lifts the pen, so the turtle moves without drawing.
`PENDOWN` or `PD`	Lowers the pen, so the turtle draws as it moves.
`HOME`	Returns the turtle to the center of the screen, pointing upwards.
`CLEARSCREEN` or `CS`	Clears the drawing area.

`SETPENCOLOR color` or `SETPC color`	Sets the pen color. `color` can be a number or a color name (e.g., `RED`, `BLUE`).
`SETPENSIZE size`	Sets the pen size to `size`. Example: `SETPENSIZE [5 5]`
`FILL`	Fills a closed shape with the current pen color.

`SHOWTURTLE` or `ST`	Makes the turtle visible.
`HIDETURTLE` or `HT`	Hides the turtle.

REPEAT count [ commands ]

Repeats the specified commands count times.

Example:

REPEAT 4 [FORWARD 50 RIGHT 90]

Draws a square.

`IF condition [ commands ]`	Executes the `commands` only if the `condition` is true. Example: `IF :x > 10 [FORWARD 50]`
`IFELSE condition [ commands_true ] [ commands_false ]`	Executes `commands_true` if the `condition` is true, otherwise executes `commands_false`. Example: `IFELSE :x > 10 [FORWARD 50] [BACK 50]`

`MAKE "variable value`	Assigns `value` to the variable named `variable`. Example: `MAKE "size 50 FORWARD :size`
`THING "variable`	Retrieves the value of a variable. Example: `SHOW THING "size`

Use TO procedure_name to start a procedure definition and END to finish it.

TO square :size
  REPEAT 4 [FORWARD :size RIGHT 90]
END

Call a procedure by simply typing its name followed by any required arguments.

square 50

TO polygon :sides :size
  REPEAT :sides [FORWARD :size RIGHT 360/:sides]
END

polygon 6 30 ; Draws a hexagon with sides of length 30

RANDOM limit

Generates a random integer between 0 and limit - 1.

Example:

FORWARD RANDOM 100

Details

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March 03, 2025 00:20

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