Data Types

StarLogo supports only a few data types: Booleans, Lists, Numbers, and Strings.

There are two booleans, true and false. There are no numeric equivalents to true and false. They must be referred to by name.

A [list of data] is a data list, similar to a list in other versions of Logo. Unlike other Logo languages, however, StarLogo does not enable you to execute a list of data as an instruction (that is, there is no run command). You can create a list of data using the list or sentence commands, or by enclosing the literal elements in []'s. (i.e. setfamily [my mother is nice]). You can create an empty list using '[]'. No elements inside the []'s are evaluated.

Note: In this version of StarLogo turtles, patches, and the observer can access a list of data.

In StarLogo, numbers have a range that is determined by the version of Java that you are using. In Sun's Java this ranges from approximately -1*10^300 to 1*10^300, and decimals can go down to about 1*10^-300. Values smaller than 1*10^-300 return a value of 0, and values larger than 1*10^300 return a value of "Infinity".

Strings are used to refer to filenames and other strings. Strings are written as a string with a quotation mark " at the beginning and the end (i.e. "foo" or "myfile.txt").

If you would like more information about how to declare variables, visit the variables page.