派生类的构造函数怎么定义？
举个例子吧：
class base1{
int x;
public:
base1(int a){x = a;}
};
//单继承
class derived1: public base1{
int a;
public:
derived1(int m, int n): base1(m){ //依次调用基类的构造函数，然后再是派生类的构造函数
a = n;
}
};
class base2{
int t;
public:
base2(int p){t = p;}
};
//多继承
class derived2: public base1,public base2{
int k;
public:
derived2(int x, int y, int z): base1(x),base2(y){ //依次调用基类构造函数，用逗号隔开，末尾没有分号
k = z;
}
};
