C 习题与解析(继承和派生-03)

文章作者 100test 发表时间 2007:03:10 16:58:28
来源 100Test.Com百考试题网

题 1. 分析以下程序的执行结果：
#include
class base
{
int n.
public:
base(){}.
base (int a)
{
cout << "constructing base class" << endl.
n=a.
cout << "n=" << n << endl.
}
~base() { cout << "destructing base class" << endl. }
}.
class subs : public base
{
int m.
public:
subs(int a, int b) : base(a)
{
cout << "constructing sub class" << endl.
m=b.
cout << "m=" << m << endl.
}
subs() { cout << "destructing sub class" << endl. }
}.
void main ()
{
subs s(1,2).
}

解：
这里base 是基类，subs为派生类，subs类的构造函数中含有调用基本类的构造函数。
所以输出为：
constructing base class
n=1
constructing sub class
n=2
destructing base class
destructing sub class