Polymorphic Data Structures in C/Glossary

A

 * Address
 * The location in memory where a variable is stored.


 * Address-of Operator
 * The ampersand (&), used to reference a variable's address instead of its value.


 * Argument
 * A variable passed to a function. The term argument is generally reserved for variables passed to main at runtime, usually from the command line interface; see parameter.

D

 * Dereference Operator
 * The asterisk (*), used to access the value that a pointer points to as opposed to the pointer itself.


 * Dereference-Member Operator
 * A hyphen, followed by a greater-than sign (->), used to access the members of a union or structure through a pointer to that construct.

G

 * Global Variable
 * A variable declared independently of a function. Global variables are accessible anywhere in a program.

L

 * Local Variable
 * A variable declared in a function's definition. Local variables can only be used in the function that declared them.

M

 * Member Operator
 * The period (.), used to access members of a union or structure.

P

 * Parameter
 * An argument passed to a function for processing. Parameters are not changed in the calling function, but rather they are copied and stored locally in the called function's runtime stack.


 * Pointer
 * A variable that stores the address of another variable, eg. a variable that "points" to a value.

S

 * Static Variable
 * A variable declared inside a function. Static variables can only be used in the function that declared them.


 * String
 * A sequence of characters terminated with a null byte. Represented in C as an array of chars, where the length is at least ( string_length + 1 ) to account for the null byte.

T

 * Type
 * See variable type.

V

 * Variable
 * A symbolic name given to a value with a known or unknown quantity. Variables always have type.


 * Variable Type
 * The way that the compiler interprets the bits stored at a variable, eg. what kind of data is stored and referenced by a variable.