Type predicates

nullp, null? - is this an empty value?
wordp, word? - is this a word?
numberp, number? - is this a number?
boolp, bool? - is this a boolean value?
arrayp, array? - is this an array?
listp, list? - is this a list?
plistp, plist? - is this a dictionary?
objectp, object? - is this an object/plot/turtle?
plotp, plot? - is this a plot?
turtlep, turtle? - is this a turtle?
funcp, func? - is this a function?
imagep, image? - is this an image?
timerp, timer? - is this a timer?

See also:

Table of Content