代码改错：#include<iostream> using namespace std; class base { private: int x; public: void setx(int n) { x = n; } void showx() { cout<<x<<endl; } }; class derived:private base { private: int y; public: void setxy(int n, int m) { setx(n); y = m; } void showxy() { cout<<x<<endl; cout<<y<<endl; } } int main() { derived obj; obj.setx(10); obj.showx(); obj.setxy(20, 30); obj.showxy(); return 0; }

代码有一个语法错误，需要在 derived 类的最后加上一个分号。

正确代码如下：

#include<iostream> 

using namespace std; 

class base { 
    private: 
        int x; 
    public: 
        void setx(int n) 
        { 
            x = n; 
        } 
        void showx() 
        { 
            cout<<x<<endl; 
        } 
}; 

class derived:private base { 
    private: 
        int y; 
    public: 
        void setxy(int n, int m) 
        { 
            setx(n); 
            y = m; 
        } 
        void showxy() 
        { 
            cout<<x<<endl; 
            cout<<y<<endl; 
        } 
}; // 添加分号

int main() { 
    derived obj; 
    obj.setx(10); 
    obj.showx(); 
    obj.setxy(20, 30); 
    obj.showxy(); 
    return 0; 
}