day04 this指针

  1 #define  _CRT_SECURE_NO_WARNINGS 
  2 #include <iostream>
  3 
  4 using namespace std;
  5 
  6 class Test
  7 {
  8 public:
  9     Test()
 10     {
 11         this->a = 0;
 12         this->b = 0;
 13     }
 14 
 15     Test(int a, int b)
 16     {
 17         this->a = a;
 18         this->b = b;
 19     }
 20 
 21     void printT()
 22     {
 23         cout << "a = " << a << ", b = " << b << endl;
 24     }
 25 
 26     int getA()
 27     {
 28         return this->a;
 29     }
 30 
 31     int getB()
 32     {
 33         return this->b;
 34     }
 35 
 36     //成员函数
 37     Test TestAdd01(Test &t1, Test &t2)
 38     {
 39         Test temp(t1.getA() + t2.getA(), t1.getB() + t2.getB());
 40         return temp;
 41     }
 42 
 43     Test TestAdd02(Test &another)
 44     {
 45         //Test temp(this->a + another.getA(), this->b + another.getB());
 46         Test temp(this->a + another.a, this->b + another.b);
 47 
 48         return temp;
 49     }
 50 
 51 
 52     void TestAdd03(Test &another)
 53     {
 54         this->a += another.a;
 55         this->b += another.b;
 56     }
 57 
 58 
 59     Test & TestAdd04(Test &another)
 60     {
 61         this->a += another.a;
 62         this->b += another.b;
 63 
 64         //返回自己
 65         return *this;
 66     }//temp引用 = *this 
 67 
 68 private:
 69     int a;
 70     int b;
 71 };
 72 
 73 //提供一个方法来实现两个Test对象相加
 74 //全局函数
 75 Test TestAdd(Test &t1, Test &t2)
 76 {
 77     Test temp(t1.getA() + t2.getA(), t1.getB() + t2.getB());
 78 
 79     return temp;
 80 }//此时会析构temp
 81 
 82 int main(void)
 83 {
 84     Test t1(10, 20);
 85     Test t2(100, 200);
 86      
 87     Test t3 = TestAdd(t1, t2); //调用了一个全局函数 
 88 
 89     t3.printT();
 90     
 91     Test t4 = t1.TestAdd01(t1, t2);
 92     t4.printT();
 93 
 94     Test t5 = t1.TestAdd02(t2); //创建临时的开销
 95 
 96     t5.printT();
 97 
 98     t1.TestAdd03(t2);
 99     t1.printT();
100 
101     (t1.TestAdd04(t2)).printT(); //t1的别名
102 
103     return 0;
104 }