标签：delete point namespace ios cond earlier and val iostream
// pointer to classes example
#include <iostream>
using namespace std;
class Rectangle {
int width, height;
public:
Rectangle(int x, int y) : width(x), height(y) {}
int area(void) { return width * height; }
};
int main() {
Rectangle obj (3, 4);
Rectangle * foo, * bar, * baz;
foo = &obj;
bar = new Rectangle (5, 6);
baz = new Rectangle[2] { {2,5}, {3,6} };
cout << "obj‘s area: " << obj.area() << ‘\n‘;
cout << "*foo‘s area: " << foo->area() << ‘\n‘;
cout << "*bar‘s area: " << bar->area() << ‘\n‘;
cout << "baz[0]‘s area:" << baz[0].area() << ‘\n‘;
cout << "baz[1]‘s area:" << baz[1].area() << ‘\n‘;
delete bar;
delete[] baz;
return 0;
}
运行结果：
obj‘s area: 12
*foo‘s area: 12
*bar‘s area: 30
baz[0]‘s area:10
baz[1]‘s area:18
指向class的指针。
This example makes use of several operators to operate on objects and pointers (operators *, &, ., ->, []). They can be interpreted as:
| expression | can be read as |
|---|---|
*x |
pointed to by x |
&x |
address of x |
x.y |
member y of object x |
x->y |
member y of object pointed to by x |
(*x).y |
member y of object pointed to by x (equivalent to the previous one) |
x[0] |
first object pointed to by x |
x[1] |
second object pointed to by x |
x[n] |
(n+1)th object pointed to by x |
Most of these expressions have been introduced in earlier chapters. Most notably, the chapter about arrays introduced the offset operator ([]) and the chapter about plain data structures introduced the arrow operator (->).
标签：delete point namespace ios cond earlier and val iostream
原文地址：https://www.cnblogs.com/CodeWorkerLiMing/p/11074570.html
