构造函数初始化列表（4）
作用：C++提供了初始化列表语法，用来初始化属性
语法：构造函数（）：属性1（值1），属性2（值2）...{}
重点：体会每种写法的相通之处和区别
1 #include <iostream> 2 using namespace std; 3 4 //初始化列表 5 class Person 6 { 7 public: 8 9 //传统的初始化操作 10 /*Person(int a, int b, int c) 11 { 12 m_A = a; 13 m_B = b; 14 m_C = c; 15 }*/ 16 17 //初始化列表初始化属性操作 18 Person() :m_A(10), m_B(20), m_C(30) 19 { 20 21 } 22 23 //另外一种写法，无论哪种写法，结果都是一样的 24 Person(int a,int b,int c) :m_A(a), m_B(b), m_C(c) 25 { 26 27 } 28 29 int m_A; 30 int m_B; 31 int m_C; 32 }; 33 34 void test_01(void) 35 { 36 //传统初始化操作，创建对象时就给它赋初值 37 /*Person p(10, 20, 30); 38 cout << "m_A = " << p.m_A << endl; 39 cout << "m_B = " << p.m_B << endl; 40 cout << "m_C = " << p.m_C << endl;*/ 41 42 //初始化列表初始化属性操作 43 /*Person p; 44 cout << "m_A = " << p.m_A << endl; 45 cout << "m_B = " << p.m_B << endl; 46 cout << "m_C = " << p.m_C << endl; */ 47 48 //另外一种写法 49 Person p(30,20,10); 50 cout << "m_A = " << p.m_A << endl; 51 cout << "m_B = " << p.m_B << endl; 52 cout << "m_C = " << p.m_C << endl; 53 } 54 55 int main(void) 56 { 57 test_01(); 58 59 system("pause"); 60 return 0; 61 }
