4: Making Decisions

block

A group of statements that are enclosed in a set of braces.

block scope

A variable may be used only in the part of the program between the variable's definition and the closing brace of the block in which the variable is defined.

conditional expression

An expression that is written using the conditional operator.

conditionally executed

A statement that is executed only when a specific condition exists.

decision structure

A set of programming statements in which an action is taken only when a specific condition exists.

flag

A bool or integer variable that signals when some condition exists in a program.

input validation

The process of inspecting data given to a program by the user and determining if it is valid.

menu

A screen displaying a set of choices from which the user selects.

menu-driven program

A program that allows the user to determine the course of action by selecting it from a list of actions.

null statement

An empty statement that does nothing.

relational expression

An expression that uses a relational operator to test one value against another value.

sequence structure

A set of programming statements that are executed in sequence.

short-circuit evaluation

Stopping the evaluation of a compound Boolean expression as soon as the expression's value can be determined.

trailing else

The last else clause that does not have an if statement following it in an if/else if construct.