c++ 类的大小

#include <iostream>using namespace std;class A1{ char c1; short i; virtual void test(){} static char c2;};class A2:public A1{ int i; virtual void test(){}};int main(){ cout<<sizeof(A1)<<endl; cout<<sizeof(A2)<<endl; return 0;}

弄明白代码的输出，也就明白了类的大小了。

 

再补充一个例子：

#include <iostream>using namespace std;class A{public: char a[3]; virtual void print(){}};class B:public virtual A{public:char a[3];virtual void print(){}};class C:public virtual B{public:char a[3];virtual void print(){}};int main(){ cout<<sizeof(A)<<endl; cout<<sizeof(B)<<endl; cout<<sizeof(C)<<endl; return 0;}