实验一
#include <iostream> #include <string> #include <vector> #include <array> template<typename T> void output1(const T& obj) { for (auto i : obj) std::cout << i << ", "; std::cout << "\b\b \n"; } template<typename T> void output2(const T& obj) { for (auto p = obj.begin(); p != obj.end(); ++p) std::cout << *p << ", "; std::cout << "\b\b \n"; } void test_array() { using namespace std; array<int, 5> x1; // 创建一个array对象,包含5个int元素,未初始化 cout << "x1.size() = " << x1.size() << endl; // 输出元素个数 x1.fill(42); // 把x1的所有元素都用42填充 x1.at(0) = 999; // 把下标为0的元素值修改为999 x1[4] = -999; // 把下表为4的元素值修改为-999 cout << "x1: "; output1(x1); // 调用模板函数output1输出x1 cout << "x1: "; output2(x1); // 调用模板函数output1输出x1 array<int, 5> x2{ x1 }; cout << boolalpha << (x1 == x2) << endl; x2.fill(22); cout << "x2: "; output1(x2); swap(x1, x2); // 交换array对象x1, x2 cout << "x1: "; output1(x1); cout << "x2: "; output1(x2); } void test_vector() { using namespace std; vector<int> v1; cout << v1.size() << endl; // 输出目前元素个数 cout << v1.max_size() << endl; // 输出元素个数之最大可能个数 v1.push_back(55); // 在v1末尾插入元素 cout << "v1: "; output1(v1); vector<int> v2{ 1, 0, 5, 2 }; v2.pop_back(); // 从v2末尾弹出一个元素 v2.erase(v2.begin()); // 删除v2.begin()位置的数据项 v2.insert(v2.begin(), 999); // 在v1.begin()之前的位置插入 v2.insert(v2.end(), -999); // 在v1.end()之前的位置插入 cout << v2.size() << endl; cout << "v2: "; output2(v2); vector<int> v3(5, 42); //创建vector对象,包含5个元素,每个元素值都是42 cout << "v3: "; output1(v3); vector<int> v4(v3.begin(), v3.end() - 2); // 创建vector对象,以v3对象的[v3.begin(), v3.end()-2)区间作为元素值 cout << "v4: "; output1(v4); } // string类基础用法 void test_string() { using namespace std; string s1{ "oop" }; cout << s1.size() << endl; for (auto& i : s1) i -= 32; s1 += "2023"; s1.append(", hello"); cout << s1 << endl; } int main() { using namespace std; cout << "===========测试1: array模板类基础用法===========" << endl; test_array(); cout << "\n===========测试2: vector模板类基础用法===========" << endl; test_vector(); cout << "\n===========测试3: string类基础用法===========" << endl; test_string(); }

2.
#include <iostream> #include <complex> // 测试标准库提供的复数类模板complex void test_std_complex() { using namespace std; complex<double> c1{ 3,4 }, c2{ 4.5 }; const complex<double> c3{ c2 }; cout << "c1 = " << c1 << endl; cout << "c2 = " << c2 << endl; cout << "c3 = " << c3 << endl; cout << "c3.real = " << c3.real() << ", " << "c3.imag = " << c3.imag() << endl; cout << "c1 + c2 = " << c1 + c2 << endl; cout << "c1 - c2 = " << c1 - c2 << endl; cout << "abs(c1) = " << abs(c1) << endl; // abs()是标准库数学函数,对复数取模 cout << boolalpha; // 设置bool型值以true/false方式输出 cout << "c1 == c2: " << (c1 == c2) << endl; cout << "c3 == c2: " << (c3 == c2) << endl; complex<double> c4 = 2; cout << "c4 = " << c4 << endl; c4 += c1; cout << "c4 = " << c4 << endl; } int main() { test_std_complex(); }

3.
#include <iostream> #include <string> using namespace std; // 类T的声明 class T { public: T(int x = 0, int y = 0); // 带有默认形值的构造函数 T(const T& t); // 复制构造函数 T(T&& t); // 移动构造函数 ~T(); // 析构函数 void set_m1(int x); // 设置T类对象的数据成员m1 int get_m1() const; // 获取T类对象的数据成员m1 int get_m2() const; // 获取T类对象的数据成员m2 void display() const; // 显示T类对象的信息 friend void func(); // 声明func()为T类友元函数 private: int m1, m2; public: static void disply_count(); // 类方法,显示当前T类对象数目 public: static const string doc; // 类属性,用于描述T类 static const int max_count; // 类属性,用于描述T类对象的上限 private: static int count; // 类属性,用于描述当前T类对象数目 }; // 类的static数据成员:类外初始化 const string T::doc{ "a simple class" }; const int T::max_count = 99; int T::count = 0; // 类T的实现 T::T(int x, int y) : m1{ x }, m2{ y } { ++count; cout << "constructor called.\n"; } T::T(const T& t) : m1{ t.m1 }, m2{ t.m2 } { ++count; cout << "copy constructor called.\n"; } T::T(T&& t) : m1{ t.m1 }, m2{ t.m2 } { ++count; cout << "move constructor called.\n"; } T::~T() { --count; cout << "destructor called.\n"; } void T::set_m1(int x) { m1 = x; } int T::get_m1() const { return m1; } int T::get_m2() const { return m2; } void T::display() const { cout << m1 << ", " << m2 << endl; } // 类方法 void T::disply_count() { cout << "T objects: " << count << endl; } // 友元函数func():实现 void func() { T t1; t1.set_m1(55); t1.m2 = 77; // 虽然m2是私有成员,依然可以直接访问 t1.display(); } // 测试 void test() { cout << "T class info: " << T::doc << endl; cout << "T objects max_count: " << T::max_count << endl; T::disply_count(); T t1; t1.display(); t1.set_m1(42); T t2{ t1 }; t2.display(); T t3{ std::move(t1) }; t3.display(); t1.display(); T::disply_count(); } // 主函数 int main() { cout << "============测试类T============" << endl; test(); cout << endl; cout << "============测试友元函数func()============" << endl; func(); }

4.
#include <iostream> #include <string> #include <iomanip> using namespace std; class Rect { public: Rect(double x = 2.0, double y = 1.0); Rect(const Rect& r); ~Rect(); double get_l() const; double get_w() const; double area()const; double circumference()const ; void resize(int times); void resize(int l_times, int w_times); private: double l, w; public: static const string doc; private: static int size; public: static int size_info(); }; void output( const Rect& r) { cout << "矩形信息: " << endl; cout << fixed << setprecision(2); cout << r.area() << endl; cout << r.get_l() << endl; cout << r.get_w() << endl; cout << r.circumference() << endl; } const string Rect::doc{ "a simple rect class" }; int Rect::size = 0; Rect::Rect(double x, double y) :l{ x }, w{ y } { ++size; l = x; w = y; } Rect::Rect(const Rect& r) :l{ r.l }, w{ r.w } { ++size; } Rect::~Rect() { --size; } double Rect::area()const { return l * w; } double Rect::circumference()const { return 2 * (l + w); } void Rect::resize(int times) { l = l * times; w = w * times; } void Rect::resize(int l_times, int w_times) { l = l * l_times; w = w * w_times; } int Rect::size_info() { return size; cout << "当前矩阵的数目为:" << size << endl; } double Rect::get_l() const { return l; } double Rect::get_w() const { return w; } void test() { cout << "矩形类信息: " << Rect::doc << endl; cout << "当前矩形对象数目: " << Rect::size_info() << endl; Rect r1; output(r1); Rect r2(4, 3); output(r2); Rect r3(r2); r3.resize(2); output(r3); r3.resize(5, 2); output(r3); cout << "当前矩形对象数目: " << Rect::size_info() << endl; } int main() { test(); cout << "当前矩形对象数目: " << Rect::size_info() << endl; }

5.
#include <iostream> #include <cmath> class Complex { public: Complex(double r = 0, double i = 0); Complex(const Complex& c); double get_real() const; double get_imag() const; void show() const; void add(const Complex& c1); private: double real, imag; public: friend Complex add(const Complex& c1, const Complex& c2) { return (c1.get_real() + c2.get_real(), c1.get_real() + c2.get_real()); } friend bool is_equal(const Complex& c1, const Complex& c2) { if (c1.real == c2.real && c1.imag == c2.imag) return 1; else return 0; } friend double abs(const Complex& c1) { return sqrt(c1.real * c1.real + c1.imag * c1.imag); } }; Complex::Complex(double r , double i ) { real = r; imag = i; } Complex::Complex(const Complex& c) { real = c.real; imag = c.imag; } double Complex::get_real() const { return real; } double Complex::get_imag() const { return imag; } void Complex::show()const { std::cout << real << "+" << (imag) << "i"; } void Complex::add(const Complex& c1) { real = real + (c1.real); imag = imag + (c1.imag); } void test() { using namespace std; Complex c1(3, -4); const Complex c2(4.5); Complex c3(c1); cout << "c1 = "; c1.show(); cout << endl; cout << "c2 = "; c2.show(); cout << endl; cout << "c2.imag = " << c2.get_imag() << endl; cout << "c3 = "; c3.show(); cout << endl; cout << "abs(c1) = "; cout << abs(c1) << endl; cout << boolalpha; cout << "c1 == c3 : " << is_equal(c1, c3) << endl; cout << "c1 == c2 : " << is_equal(c1, c2) << endl; Complex c4; c4 = add(c1, c2); cout << "c4 = c1 + c2 = "; c4.show(); cout << endl; c1.add(c2); cout << "c1 += c2, " << "c1 = "; c1.show(); cout << endl; } int main() { test(); system("pause"); }

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