++ , , , struct, union, enum.
//C
enum day{sun,mon,tue,wen};
struct path{char str[30];
enum day Week;}
struct path Link;
//C++
enum day{sun,mon,tue,wen};
struct path{char str[30];
day Week;}
path List;
, .
struct Goods{
char *name;
union{double d, long l, int i)};
};
++ :
- ;
;
;
;
;
;
;
;
;
.
++:
, .
, ( , , - ).
, , .
, , .
. .
, . .
++ 2 : , , . . . . - . .
3 : public, private protected. , .
int var;
class Ex
{
public:
f(){var =0};
private:
int var; //
}
.
class Point2D
{
double x,y;
public:
Point2D(double x, double y)
{
Point2D::x=x;
Point2D::y=y;
}
}
exteen int count;
struct POINT;
class Point2D;
, .. , .
|
|
static.
- .
- , . .
- , . ++ new delete.
, - , . , , , . , , static.
class Point2D
{
double x,y;
static int count;
public:
Point2D(double x, double y)
{
x=_x;
y=_y;
count++;
}
~Point2D()
{
count--;
}
};
//point2d.cpp
int Point2D::count;
. - . .
//
cout<<Point2D::Count<<\n;
, -, .
static int GetCount()
{
return count;
}
cout<<Point2D::GetCount();
, this .
: . , .