填空题

下列程序输出结果为：
#include＜iostream＞
using namespace std;
class TestClass1

public:
TestClass1()
TestClass1(int i)

x1=i;

void dispa()

cout＜＜"x1="＜＜x1＜＜",";

private:
int x1;
;
class TestClass2:public TestClass1

public:
TestClass2()
TestClass2(int i):TestClass1(i+10)

x2=i;

void dispb()

dispa();
cout＜＜"x2="＜＜x2＜＜endl;

private:
int x2;
;
int main()

TestClass2 b(2);
b.dispb();
return 0;