KeytermDefined Terms | C Primer Plus (5th Edition)

Defined Terms

argument: A value passed to a function when it is called.

block: Sequence of statements enclosed in curly braces.

buffer: A region of storage used to hold data. IO facilities often store input (or output) in a buffer and read or write the buffer independently of actions in the program. Output buffers usually must be explicitly flushed to force the buffer to be written. By default, reading cin flushes cout; cout is also flushed when the program ends normally.

built-in type: A type, such as int, defined by the language.

cerr: ostream object tied to the standard error, which is often the same stream as the standard output. By default, writes to cerr are not buffered. Usually used for error messages or other output that is not part of the normal logic of the program.

cin: istream object used to read from the standard input.

class: C++ mechanism for defining our own data structures. The class is one of the most fundamental features in C++. Library types, such as istream and ostream, are classes.

class type: A type defined by a class. The name of the type is the class name.

clog: ostream object tied to the standard error. By default, writes to clog are buffered. Usually used to report information about program execution to a log file.

comments: Program text that is ignored by the compiler. C++ has two kinds of comments: single-line and paired. Single-line comments start with a //. Everything from the // to the end of the line is a comment. Paired comments begin with a /* and include all text up to the next */.

condition: An expression that is evaluated as true or false. An arithmetic expression that evaluates to zero is false; any other value yields true.

cout: ostream object used to write to the standard output. Ordinarily used to write the output of a program.

curly brace: Curly braces delimit blocks. An open curly ({) starts a block; a close curly (}) ends one.

data structure: A logical grouping of data and operations on that data.

edit-compile-debug: The process of getting a program to execute properly.

end-of-file: System-specific marker in a file that indicates that there is no more input in the file.

expression: The smallest unit of computation. An expression consists of one or more operands and usually an operator. Expressions are evaluated to produce a result. For example, assuming i and j are ints, then i + j is an arithmetic addition expression and yields the sum of the two int values. Expressions are covered in more detail in Chapter 5.

for statement: Control statement that provides iterative execution. Often used to step through a data structure or to repeat a calculation a fixed number of times.

function: A named unit of computation.

function body: Statement block that defines the actions performed by a function.

function name: Name by which a function is known and can be called.

header: A mechanism whereby the definitions of a class or other names may be made available to multiple programs. A header is included in a program through a #include directive.

if statement: Conditional execution based on the value of a specified condition. If the condition is true, the if body is executed. If not, control flows to the statement following the else if there is one or to the statement following the if if there is no else.

iostream: library type providing stream-oriented input and output.

istream: Library type providing stream-oriented input.

library type: A type, such as istream, defined by the standard library.

main function: Function called by the operating system when executing a C++ program. Each program must have one and only one function named main.

manipulator: Object, such as std::endl, that when read or written "manipulates" the stream itself. Section A.3.1 (p. 825) covers manipulators in more detail.

member function: Operation defined by a class. Member functions ordinarily are called to operate on a specific object.

method: Synonym for member function.

namespace: Mechanism for putting names defined by a library into a single place. Namespaces help avoid inadvertent name clashes. The names defined by the C++ library are in the namespace std.

ostream: Library type providing stream-oriented output.

parameter list: Part of the definition of a function. Possibly empty list that specifies what arguments can be used to call the function.

preprocessor directive: An instruction to the C++ preprocessor. #include is a preprocessor directive. Preprocessor directives must appear on a single line. We'll learn more about the preprocessor in Section 2.9.2.

return type: Type of the value returned by a function.

source file: Term used to describe a file that contains a C++ program.

standard error: An output stream intended for use for error reporting. Ordinarily, on a windowing operating system, the standard output and the standard error are tied to the window in which the program is executed.

standard input: The input stream that ordinarily is associated by the operating system with the window in which the program executes.

standard library: Collection of types and functions that every C++ compiler must support. The library provides a rich set of capabilities including the types that support IO. C++ programmers tend to talk about "the library," meaning the entire standard library or about particular parts of the library by referring to a library type. For example, programmers also refer to the "iostream library," meaning the part of the standard library defined by the iostream classes.

standard output: The output stream that ordinarily is associated by the operating system with the window in which the program executes.

statement: The smallest independent unit in a C++ program. It is analogous to a sentence in a natural language. Statements in C++ generally end in semicolons.

std: Name of the namespace used by the standard library. std::cout indicates that we're using the name cout defined in the std namespace.

string literal: Sequence of characters enclosed in double quotes.

uninitialized variable: Variable that has no initial value specified. There are no uninitialized variables of class type. Variables of class type for which no initial value is specified are initialized as specified by the class definition. You must give a value to an uninitialized variable before attempting to use the variable's value. Uninitialized variables can be a rich source of bugs.

variable: A named object.

while statement: An iterative control statement that executes the statement that is the while body as long as a specified condition is true. The body is executed zero or more times, depending on the truth value of the condition.

() operator: The call operator: A pair of parentheses "()" following a function name. The operator causes a function to be invoked. Arguments to the function may be passed inside the parentheses.

++ operator: Increment operator. Adds one to the operand; ++i is equivalent to i = i+ 1.

+= operator: A compound assignment operator. Adds right-hand operand to the left and stores the result back into the left-hand operand; a += b is equivalent to a =a + b.

. operator: Dot operator. Takes two operands: the left-hand operand is an object and the right is the name of a member of that object. The operator fetches that member from the named object.

:: operator: Scope operator. We'll see more about scope in Chapter 2. Among other uses, the scope operator is used to access names in a namespace. For example, std::cout says to use the name cout from the namespace std.

= operator: Assigns the value of the right-hand operand to the object denoted by the left-hand operand.

<< operator: Output operator. Writes the right-hand operand to the output stream indicated by the left-hand operand: cout << "hi" writes hi to the standard output. Output operations can be chained together: cout << "hi << "bye" writes hibye.

>> operator: Input operator. Reads from the input stream specified by the left-hand operand into the right-hand operand: cin >> i reads the next value on the standard input into i. Input operations can be chained together: cin >> i >> j reads first into i and then into j.

== operator: The equality operator. Tests whether the left-hand operand is equal to the right-hand.

!= operator: Assignment operator. Tests whether the left-hand operand is not equal to the right-hand.

<= operator: The less-than-or-equal operator. Tests whether the left-hand operand is less than or equal to the right-hand.

< operator: The less-than operator. Tests whether the left-hand operand is less than the right-hand.

>= operator: Greater-than-or-equal operator. Tests whether the left-hand operand is greater than or equal to the right-hand.

> operator: Greater-than operator. Tests whether the left-hand operand is greater than the right-hand.