sizeof(類型名)
或者
sizeof(表達式)
例如:
sizeof(int)
#include<iostream.h>
void main()
{
short s;
int i;
char c;
float f;
double d;
cout<<"please input a duan zhengshu: ";
cin>>s;
cout<<"please input a zhengshu: ";
cin>>i;
cout<<"please input a zifu: ";
cin>>c;
cout<<"sizeof("<<s<<")="<<sizeof(s)<<endl;
cout<<"sizeof("<<i<<")="<<sizeof(i)<<endl;
cout<<"sizeof("<<c<<")="<<sizeof(i)<<endl;
}