Predefined Properties

Logo has quite a few built-in objects, the most well-known being the TURTLE object. This section documents the properties of these objects.

Most properties are both readable and writeable. A few properties are read-only. An attempt to change such a property is ignored.

Properties provide an easy way to manipulate turtles, controls, or panels. As an example, you could change the drawing color of turtle #0 like this:

PPROP 0 "PENCOLOR "RED

Similarly, the GPROP command lets you read the turtle’s current pen color:

GPROP 0 "PENCOLOR

Some properties are callable properties. To call a property, use the CPROP command as in this example:

(CPROP "LISTBOX "APPEND "|Some text|)