296 Glossary
algorithm A set of steps for performing a task, like a recipe.
animation The illusion of motion created when similar images
are displayed quickly one after the other, as in a cartoon.
app Short for application, a computer program that does some-
thing useful (or fun!).
append To add something to the end; for example, adding letters
onto the end of a string or adding elements to the end of a list or
a r ray.
argument A value passed to a function; in the statement
range(10), 10 is an argument.
array An ordered list of values or objects, usually of the same
type, accessed by their index, or position in the list.
assignment Setting the value of a variable, as in x = 5, which
assigns the value 5 to the variable x.
block A group of programming statements.
Boolean A value or expression that can be either true or false.
class A template defining the functions and values to be con-
tained in any objects of that type.
code Statements or instructions written by a programmer in a
language that computers can understand.
collision detection Checking to see if two virtual objects are
touching, or colliding, on the screen, like the ball and paddle
in Pong.
concatenate To combine two strings of text into a single string.
conditional expression A statement that allows the computer
to test a value and perform different actions depending on the out-
come of that test.
constant A named value in a computer program that stays the
same, like math.pi (3.1415...).
declaration A statement or group of statements that tell a com-
puter what a variable or function name means.