qfedu-cpp-level/day7/d3.cpp

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2023-08-01 18:51:53 +08:00
// 类模版
// 类模版是成员变量的数据类型泛化
// 类模版的声明作用于整个类,而不是单个成员,即类的内部的任何位置都可以使用
// 如: 定义长方形的图形类
#include <iostream>
#include <cstring>
#include <cstdlib>
using namespace std;
// 类模版
template <typename T>
class Rectangle
{
private:
T width, height; //矩形的宽和高
public:
Rectangle(T w, T h) : width(w), height(h) {}
public:
void draw()
{
cout << "绘制矩形"
<< "宽: " << width << "高: " << height << endl;
}
void length()
{
cout << "矩形周长: " << 2 * (width + height) << endl;
}
};
int main()
{
cout << "r1: " << endl;
Rectangle<int> r1(10, 20);
r1.draw();
r1.length();
cout << "r2: " << endl;
Rectangle<double> r2(10.53, 20.25);
r2.draw();
r2.length();
cout << "r3: " << endl;
Rectangle<float> r3(10.2f, 20.2f);
r3.draw();
r3.length();
return 0;
}