Glossary D...I

dead code	Part of a program that can never be executed, often because it appears after a return statement.
debugging	The process of finding and removing any of the three kinds of errors.
declaration	A statement that creates a new variable and determines its type.
decrement	Decrease the value of a variable by one. The decrement operator in C++ is --.
deep equality	Equality of values. Two references that point to objects that have the same value.
delete	an operator that returns the memory pointed to by a pointer to the free store (a special pool of free memory that each program has)
delimiter	A character that is used to separate tokens, like the punctuation in a natural language.
deterministic	A program that does the same thing every time it is run.
development plan	A process for developing a program. In this chapter, I demonstrated a style of development based on developing code to do simple, specific things, and then encapsulating and generalizing.
dictionary	Another name for a table.
dot notation	The method C++ uses to refer to member variables and functions. The format is className.memberName.
dynamic memory allocation	the explicit allocation of contiguous blocks of memory at any time in a program.
element	One of the values in a vector. The [] operator selects elements of a vector.
encapsulate	To divide a large complex program into components (like functions) and isolate the components from each other (for example, by using local variables).
encode	To represent one set of values using another set of values, by constructing a mapping between them.
entry	An element in a table that contains a key-value pair.
exception	A run time error. Exceptions cause the execution of a program to terminate.
executable	Another name for object code that is ready to be executed.
explicit	Anything that is spelled out completely. Within a nonmember function, all references to the instance variables have to be explicit.
expression	A combination of variables, operators and values that represents a single result value. Expressions also have types, as determined by their operators and operands.
FIFO	"first in, first out," a queueing discipline in which the first member to arrive is the first to be removed.
fill-in function	A function that takes an "empty" object as a parameter and fills it its instance variables instead of generating a return value.
flag	A variable (usually type bool) that records a condition or status information.
floating-point	A type of variable (or value) that can contain fractions as well as integers. There are a few floating-point types in C++; the one we use in this book is double.
formal language	Any of the languages people have designed for specific purposes, like representing mathematical ideas or computer programs. All programming languages are formal languages.
fractal	A kind of image that is defined recursively, so that each part of the image is a smaller version of the whole.
function declaration	A statement that declares the interface to a function without providing the body. Declarations of member functions appear inside structure definitions even if the definitions appear outside.
function	A named sequence of statements that performs some useful function. Functions may or may not take parameters, and may or may not produce a result.
functional programming style	A style of program design in which the majority of functions are pure.
garbage collection	The process of finding objects that have no references and reclaiming their storage space.
generalize	To replace something unnecessarily specific (like a constant value) with something appropriately general (like a variable or parameter). Generalization makes code more versatile, more likely to be reused, and sometimes even easier to write.
generic data structure	A kind of data structure that can contain data of any type.
hash code	The integer value that corresponds to a given value.
hash function	A function that maps values of a certain type onto integers.
hash table	A particularly efficient implementation of a table.
heapsort	Yet another sorting algorithm.
helper function	Often a small function that does not do anything enormously useful by itself, but which helps another, more useful, function.
high-level language	A programming language like C++ that is designed to be easy for humans to read and write.
histogram	A vector of integers where each integer counts the number of values that fall into a certain range.
implementation	The body of a function, or the details of how a function works.
implicit	Anything that is left unsaid or implied. Within a member function, you can refer to the instance variables implicitly (without naming the object).
increment	Increase the value of a variable by one. The increment operator in C++ is ++. In fact, that's why C++ is called C++, because it is meant to be one better than C.
index	A variable or value used to select one of the members of an ordered set, like a character from a string, or the element of a vector.
infinite loop	A loop whose condition is always true.
infinite recursion	A function that calls itself recursively without every reaching the base case. Eventually an infinite recursion will cause a run-time error.
infix	A way of writing mathematical expressions with the operators between the operands.
initialization	A statement that declares a new variable and assigns a value to it at the same time.
inorder	A way to traverse a tree, visiting the left subtree, then the root, then the right subtree.
instance variable	One of the named data items that make up an structure. Each structure has its own copy of the instance variables for its type.
instance	An example from a category. My cat is an instance of the category "feline things." Every object is an instance of some type.
interface	A description of how a function is used, including the number and types of the parameters and the type of the return value.
interpret	To execute a program in a high-level language by translating it one line at a time.
invariant	A condition, usually pertaining to an object, that should be true at all times in client code, and that should be maintained by all member functions.
invoke	To call a function "on" an object, in order to pass the object as an implicit parameter.
iteration	One pass through (execution of) the body of the loop, including the evaluation of the condition.