【面试题】sizeof 获取自定义类，结构体，vector，地图，string的占内存大小

【面试题】sizeof 获取自定义类，结构体，vector，map，string的占内存大小

#include <iostream>
#include <vector>
#include <map>
#include <string>
using namespace std;

struct a
{
	short aa;//2
	short b;//2
	short c;//2
};//6

struct b
{
	char x;//1
	char y;//1
	char z;//1
	short q;//2
};//6

class c
{
private:
	int a;//4
	char b;//1
	short x;//2
public:
	c();
	~c();
	void print();
	virtual void function();
};//12

class d : public c
{
private:
	char *pData;
public:
	d();
	~d();
	virtual void otherfunction();
};//16




void main()
{
	cout << sizeof(a)<<endl;
	cout << sizeof(b) <<endl;
	cout << sizeof(c) <<endl;
	cout << sizeof(d) <<endl;
	
	vector<int> v_int;//20
	vector<double> v_double;//20

	vector<a> v_a;//20

	cout << sizeof(v_int) <<endl;
	cout << sizeof(v_double) <<endl;
	cout << sizeof(v_a) <<endl;

	string str;//32
	cout << sizeof(str)<<endl;

	map<string,int> m_string;//28
	cout << sizeof(m_string) <<endl;

	map<int,int> m_int;//28
	cout << sizeof(m_int) <<endl;

}