操作符核心示例

++与==操作符

class Vector {

private:
    int x;
    int y;
public:
    int getX() {
        return x;
    }
    int getY() {
        return y;
    }

    Vector operator + (Vector& vector) {
        cout << "+运算符重载" << endl;
        this->x = this->x + vector.getX();
        this->y = this->y + vector.getX();
        return Vector(x, y);
    }

    Vector operator ++ (int) {
        cout << "后置++" << endl;
        this->x = this->x + 1;
        this->y = this->y + 1;
        return Vector(x, y);
    }

    Vector operator ++ () {
        cout << "前置++" << endl;
        this->x = this->x + 1;
        this->y = this->y + 1;
        return Vector(x, y);
    }

    bool operator == (const Vector& v) {
        cout << "==运算符重载 "<<this->x << endl;
        cout << "==运算符重载 "<<this->y << endl;
        cout << "==运算符重载 "<<v.x << endl;
        cout << "==运算符重载 "<<v.y << endl;
        bool result = this->x == v.x && this->y == v.y;
        return result;
    }

    Vector(int x, int y) {
        cout << "普通构造函数" << endl;
        this->x = x;
        this->y = y;
    }

    Vector(const Vector& vector) {
        cout << "拷贝构造函数" << endl;
        this->x = vector.x;
        this->y = vector.y;
    }

    ~Vector() {
        cout << "析构函数" << endl;
    }

    friend ostream& operator << (ostream& _Ostr,
        const Vector& v) {
        cout << v.x << "  " << v.y;
        return _Ostr;
    }
};

void main() {
    Vector v1(1, 2);
    Vector v2(1, 2);
    Vector v = v1 + v2;
    v++;
    cout << (v1 == v2) << endl;
    ++v;
    cout << v.getX() << " " << v.getY() << endl;
    cout << v << endl;
    getchar();
}

运行结果

普通构造函数
普通构造函数
+运算符重载
普通构造函数
后置++
普通构造函数
析构函数
==运算符重载 2
==运算符重载 3
==运算符重载 1
==运算符重载 2
0
前置++
普通构造函数
析构函数
4 5
4  5

[]操作符

class Array 
{
public:
    Array(int size) {
        this->size = size;
        this->array = (int *)malloc(sizeof(int)*size);
    }
    ~Array() {
        if (this->array)
        {
            free(this->array);
            this->array = NULL;
        }
    }

    int& operator [](int index) 
    {
        return this->array[index];
        //return *(array + index);
    }

    void set(int index,int value) 
    {
        this->array[index] = value;
        //*(array + index) = value;
    }
    void printArray() 
    {
        for (int i = 0; i < size; i++)
        {
            //cout<<array[i]<<endl;
            cout<<*(array+i)<<endl;
        }
    }
private:
    int size;
    int* array;
};

void main() {
    Array *arr = new Array(6);
    arr->set(0,8);
    arr->set(1,9);
    arr->set(2,10);
    (*arr)[3] = 11;
    (*arr)[4] = 12;
    (*arr)[5] = 13;
    arr->printArray();
    delete(arr);
    getchar();
}

运行结果

8
9
10
11
12
13