对于下面代码说法正确的有 class A { public: A(int x) {} }; class B: public A{ public: B(){} }; int main() { B b; }A.编译错误B.编译正确,但是运行时没有输出信息C.在第三行代码后加上 A() = default; 就能编译通过D.在第二行代码后加上 A() {} 就能编译通过E.第七行改成 B():A(0){} 就能编译通过

对于下面代码说法正确的有 class A { public: A(int x) {} }; class B: public A{ public: B(){} }; int main() { B b; }

A.编译错误

B.编译正确,但是运行时没有输出信息

C.在第三行代码后加上 A() = default; 就能编译通过

D.在第二行代码后加上 A() {} 就能编译通过

E.第七行改成 B():A(0){} 就能编译通过


参考答案和解析
编译错误;在第三行代码后加上 A() = default; 就能编译通过;在第二行代码后加上 A() {} 就能编译通过;第七行改成 B():A(0){} 就能编译通过

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