C Programming

definition

A declaration that reserves storage.

nested loop

A loop that is contained within another loop.

character constant

A single character that is written in single quotes.

label

An identifier that is followed by a colon.

operand

An object that can be manipulated by an operator.

assignment

An operator that assigns a value to a memory location associated with a variable name.

char

1. A variable type that stores characters. 2. A data type that specifies one character.

float

1. A variable type that stores decimal numbers. 2. A data type that specifies a single-precision fractional number.

double

1. A variable type that stores high-precision decimal numbers. 2. A data type that specifies a double-precision fractional number.

int

1. A variable type that stores integers. 2. A data type that specifies an integer number.

library files

A collection of binary files that can be customized. It is used to contain functions that are already compiled and ready for use.

library

A collection of object files that are gathered together.

expression

A combination of constants, operators, and variables that has a data type and generates a value.

floating-point constant

A constant that can be positive or negative and can be written using numeric or scientific notation. It defaults to type double and can also be long or unsigned.

integer constant

A constant that can consist of any combination of the digits 0 to 9.

data type

A data classification that defines the values that a variable can store.

linked list

A data list that is implemented as a dynamic data structure that uses a series of objects of like type.

pointer

A data object that contains an address to another data object.

extern

A data type modifier that notifies the compiler of a type of variable without reserving storage for it because it is already defined elsewhere in the program.

bit manipulation

A feature of C that enables operations to work at the bit level.

loop

A feature that allows a set of instructions to be repeated until a certain condition is reached.

fscanf()

A function that accepts input from a file. It is a variation of the scanf() function.

printf()

A function that allows a program to print characters to the screen.

change_struct()

A function that assigns different values to the structure members.

realloc()

A function that changes the size of the memory allocated to some specified size. It frees allocated memory and makes it available to the system heap.

ferror()

A function that checks whether a file operation has produced an error. If it has, it returns a nonzero value.

feof()

A function that checks whether an end-of-file condition is encountered. If so, it returns a nonzero value. See also EOF.

fclose()

A function that closes a file when it is called.

filecopy()

A function that copies the contents of an input file to an output file.

getchar()

A function that gets a character from standard input and assigns the data to a variable.

ftell()

A function that obtains the current value of the file position indicator for a stream.

fopen()

A function that opens a file when it is called.

fprintf()

A function that places output in a file identified by a file pointer.

fgets()

A function that reads a line from an input file into a character array.

fread()

A function that reads from a file into a buffer region of memory.

malloc()

A function that returns a pointer to a specified amount of memory. See also the calloc() and realloc() functions.

calloc()

A function that returns a pointer to an array of allocated memory. See also the malloc() and realloc() functions.

free()

A function that returns memory back to the heap.

fseek()

A function that sets the file position locator.

putchar()

A function that uses standard output to write a character to the standard output device.

fwrite()

A function that writes from a region of memory to a file.

goto

A jump statement that is used to transfer control from one place to another in a program.

break

A jump statement that is used to transfer control out of a loop when a condition occurs that the loop test is not looking for. It can only be used with a switch or an iteration statement.

continue

A jump statement that transfers control back to the beginning of the loop, bypassing any statements that are not yet executed. It can be used only in an iteration statement.

do-while

A looping statement that is used in situations where it is required to execute a loop at least once.

for

A looping statement that is used on a program that must perform an operation a fixed number of times. See also while and do-while.

exponent

A part of a floating-point variable that indicates the power of ten by which the value of the number is multiplied. See also mantissa.

compiler

A piece of software that translates a C program into machine code.

heap

A portion of memory that is reserved for a program. It is used for the temporary storage of data structures.

recursion

A process in which a function can call itself. It is useful for carrying out tasks that need to be performed repeatedly.

indirection

A process in which a pointer points to a targeted value.

nesting

A process in which an object is embedded in another object of the same type.

linking

A process in which different pieces of object code are combined.

call by reference

A process in which the parameters of a calling function are passed to the parameters of the called function using an address. See also call by value.

call by value

A process in which the values of the actual parameters sent by the calling function are copied to the formal parameters of the called function. See also call by reference.

iteration

A process that allows repeated execution of code a fixed number of times or until a condition is satisfied.

initialize

A process that assigns an initial value to an object.

double indirection

A process that passes pointers to other pointers. It can be used to indirectly refer to data objects of any type.

declaration

A process that specifies the interpretation given to a variable.

C

A programming language that consists of a collection of functions. It was created by Dennis Ritchie in 1972.

associativity

A rule that defines the order in which operators (at the same level of precedence) will be evaluated in an expression: either left to right or right to left.

precedence

A rule that identifies the operator that has the highest rank and evaluates the operation based on it.

bit field

A set of adjacent bits that are contained within a single storage unit.

bitwise operator

A special operator that is used to manipulate bits directly. It can only be applied to integral operands.

escape sequence

A statement that consists of multiple escape characters and that is used to format output.

if-else

A statement that executes an if statement if an expression is evaluated as TRUE. If the expression is FALSE, the else statement is executed.

else

A statement that is used with an if statement to execute an alternate statement if an expression is FALSE. See also if-else.

jump statement

A statement that performs an unconditional transfer from one part of a program to another.

if

A statement that selects or ignores a single action. See also else.

flow control statement

A statement that specifies the order in which tasks are executed in a programming language.

register

A storage specifier that enables fast access to an object. This generally occurs by requesting that the compiler retain the value of the variable in the machine register.

operator

A symbol that specifies what mathematical operations are to be performed on a variable or group of variables. See also operand.

header file

A text file that contains prototypes for a standard library. It can also contain preprocessor directives and declarations of variables that are shared by several files.

preprocessor

A text processor that manipulates the text of a source file as part of the first phrase of translation.

enumeration

A type of variable that provides a list of named constants.

main()

A user-defined function that informs a C program to allow other functions to be called to perform specific operations.

loader

A utility that processes object code from the compiler and combines it with object code from the library routines to ensure that all functions called in the code are included in the final program.

argument

A value that is used in a call of a function.

constant

A value that must remain the same in the course of a program.

identifier

A variable name that refers directly to the data stored in a particular memory location.

global variable

A variable that is defined once and can be available to an entire program.

logical operator

Also known as a Boolean operator, an operator that checks if expressions have a nonzero (TRUE) or a zero (FALSE) value.

comma operator

Also known as the sequential evaluation operator, an operator that causes a list of expressions to be evaluated in turn, from left to right.

EOF

An abbreviation for end-of-file, a constant that is used to identify when to stop processing - this happens when the end of the file has been reached.

literal constant

An actual character or value that is in a program.

array

An aggregate data object that stores similar data elements contiguously in memory. See also subscript.

reference

An alias for a specific object that currently exists. Accessing a reference will manipulate the object to which it is aliased.

NULL

An implementation-dependent null pointer constant that is often defined as binary zero.

function

An independent subroutine that carries out a specific task required by the main program.

macro

An instruction that contains other instructions.

preprocessor directive

An instruction to the compiler to change the source code before compilation.

factorial

An integer calculation that is determined by multiplying all the integers from one up to the integer being processed.

modulus

An operator that provides a remainder facility to find the remainder when one number is divided by another.

binary operator

An operator that works on two operands. See also ternary operator and unary operator.

command-line argument

Information that supplies additional character sequences following a program name on the command-line.

AND

Represented as &&, a logical operator that returns 1 (TRUE) if both its operands are nonzero, and otherwise returns zero (FALSE).

NOT

Represented as the ! symbol, a logical operator that returns zero (FALSE) if its operand is not zero, and 1 (TRUE) if its operand is zero.

OR

Represented as the || symbols, a logical operator that returns 1 (TRUE) if one or both of its operands are nonzero, and otherwise returns zero (FALSE).

null character

The character \0 that's used to terminate a string.

mantissa

The value of a number that is stored for a floating-point variable. See also exponent.