COMP 206 Unit 3: The C in C++

Pregunta	Respuesta
function prototype	uses description of types of arguments when declaring/defining function
Components of function prototype	- name - input parameters (parentheses) - type of return value (or void)
void	specifies that no value is returned
return	- returns value from function - exits function back to point right after function
Purpose of C Library	someone already solved your problem and gave it more thought and debugging
Using C Function Library	- find programming reference - description of function demonstrates syntax of code - has at least one #include line, showing you header file containing function prototype - duplicate #include line in file so function is properly declared
librarian	manages groups of object modules
5 Execution Control Statements	- if-else - while - do-while - for - switch
if-else	if(expression) statement else statement - if condition is true, first statement is executed; if it is false, second statement is executed
while	while(expression) statement - statement repeats until controlling expression evaluates to false
do-while	do statement while(expression); - statement always executes at least once, even if expression evaluates to false first time
for	for(initialization; conditional; step) statement -allows you to execute block of code specified number of times
initialization	code executes once at very beginning
conditional	tested before each iteration
step	executes at end of each loop
break	quits loop without executing rest of statements in loop
continue	stops execution of current iteration and goes back to beginning of loop to begin new iteration
while(true)	do loop forever
switch	statement selects from among pieces of code based on value of integral expression switch(selector) { case integral-value 1 : statement; break; case integral-value 2 : statement; break; (...) default: statement; }
goto	- statement used to jump from anywhere to anywhere within a function - makes it difficult to trace control of flow of program
recursion	programming technique whereby you call function you're in - function calls itself directly/indirectly
Basic Operators	addition: + subtraction/unary minus: - multiplication: * division: / assignment: = modulus: % ; remainder from division
precedence	defines order in which expression evaluates when several different operators are present
auto-decrement operator	-- ; decrease by one unit
auto-increment operator	++ : increase by one unit
++A	operation first performed and resulting value is produced
A++	current value is produced, and then operator is performed
Basic Data Types	- char - int - float - double
char	character storage and uses minimum of 8 bits
int	stores integral number and uses minimum of two bytes of storage
float	single-precision floating point; 4 bytes
double	double-precision floating point; 8 bytes
bool	two states expressed by the built-in constants true (converts to integral one) and false (converts to integral zero)
long	modify max value data type will hold
short	modify min value data type will hold
signed	represent both positive and negative values
unsigned	integer can never be negative
pointer	type of variable that holds an address
dereference	access or manipulate data contained in memory location pointed to by a pointer; *
address	location of object in memory; &
reference	alternative name for an existing variable
pass by value	pass arguments to function, copy of argument is made inside function
pass by reference	parameter becomes alias for argument; argument and parameter refer to same area of storage
Purpose of Pointer	hold address and use address to modify original value
Pointer vs Reference	- pointers store address of variable - references refer to existing variable in another name
scoping	tells you where variable is valid, where it is created, and where it gets destroyed
"goes out of scope"	where variable gets destroyed
on the fly	allows you to define variables anywhere in scope, so you can define variable right before you use it
global variable	defined outside all function bodies and are available to all parts of program
local variable	occur within scope; automatically come into being when scope is entered and automatically go away when scope closes
register	make access to variable as fast as possible
static	- value is extant throughout life of program - initialization is performed only first time function is called - unavailable outside scope of function, so it can't be inadvertently changed
extern	tells compiler that variable/function exists, even if compiler hasn't yet seen it in file currently being compiled
const	represents constant
volatile	prevents compiler from performing any optimizations based on stability of variable
const vs volatile	- const variable cannot be changed - volatile can change at any time
static vs volatile	- static variable initialization is performed only first time function is called, data retains its value between function calls -volatile variable always read whenever value is required, even if it was just read line before
Relational Operators	less than: < greater than: > less than/equal to: <= greater than/equal to: >= equivalent: == not equivalent: !=
Logical Operators	true: non-zero value false: zero value and: && or: \|\|
Bitwise Operators	manipulate individual bits in number and: &; produces one in output bit if both input bits are 1; otherwise produces 0 or: \|; produces one in output bit if either input bit is 1; produces 0 if both input bits are 0 xor: ^; produces 1 in output bit if one or other input bit is 1, but not both not: ~; only takes one argument; ones complement operator nor: opposite of input bit; 1 if input is 0; 0 if input is 1
Shift Operators	left-shift operator: <<; produces operand to left of operator shifted to left by number of bits specified after operator right-shift operator: >>; produces operand to left of operator shifted to right by number of bits specified after operator
Unary Operators	logical not: !; takes true value and produces false value unary minus: - ; produces negative of value unary plus: + ; provides symmetry with unary minus address-of (&) and dereference (* and ->): used with pointers
ternary operator	if-else: - three operands - a = --b ? b : (b = -99)
comma operator	- separate variable names in multiple definitions - used in function argument lists - used as operator to separate expression
cast	changes one type of data into another
static_const	- typical castless conversions - narrowing conversions -forcing conversion from void* -implicit type conversions -static navigation of class hierarchies
const_cast	convert from const to nonconst or from volatile to nonvolatile
reinterpret_cast	pretends object is bit pattern that can be treated as if it were an entirely different type of object
sizeof	gives info about amount of memory allocated for data items
asm	escape mechanism that allows you to write assembly code for your hardware within C++ program
aliasing	situation where two different expressions or symbols refer to same object
typedef	create alias that can be used anywhere in place of type name
struct	collects groups of variables into structure
enum	automatically enumerates any list of identifiers you give it by assigning them values of 0, 1, 2, etc.
union	piles all data into single space
array	-clumps variables together, one right after the other, under single identifier name -set of consecutive memory locations used to store data
array identifier	hook into square-bracket syntax; read-only pointer to beginning of array
pointer arithmetic	- cannot add two pointers -if you subtract pointers, result is number of elements between two pointers - can add/subtract integral value and pointer
preprocessor debugging flag	#define: defines one or more debugging flags #ifdef: test flags #undef: removes code
assert()	convenient debugging macro; in standard header file <cassert>
NDEBUG	flag used to <cassert> to change way code is generated by macros
function pointer	variable that stores address of function; allows you to pass and store functions to variables
separate compilation	breaking code into number of translation units
make	utility that allows programmer to manage compilation and linking of separate program units (source files) and libraries
makefile	text file that contains instructions for make; description of how to compile program
macros	allow convenient string replacement; invoke C++ compiler
target	file that you want rebuilt
Use of Macros	- = : used to identify macro - $ and () : expand macro

Siguiente

Descripción

Resumen del Recurso

Similar

	Creado por Adriana Vincelli-Joma hace alrededor de 3 años