sizeof

#include <iostream>

using namespace std;

int main() {
//用 sizeof 计算各类种常量的字节长度
cout << "sizeof('$') = " << sizeof('$') << endl;
cout << "sizeof(1) = " << sizeof(1) << endl;
cout << "sizeof(1.5) = " << sizeof(1.5) << endl;
cout << "sizeof("Good!" ) = " << sizeof("Good!") << endl;

//用sizeof 计算各类型变量的字节长度
int i = 100;
char c = 'A';
float x = 3.14159;
double p = 0.1;
cout << endl;
cout << "sizeof(i) = " << sizeof(i) << endl;
cout << "sizeof(c) = " << sizeof(c) << endl;
cout << "sizeof(x) = " << sizeof(x) << endl;
cout << "sizeof(p) = " << sizeof(p) << endl;
cout << endl;
 
//用sizeof 计算表达式的字节长度
cout << "sizeof(x+1.732)=" << sizeof(x + 1.732) << endl;
cout << endl;
 
//用sizeof 计算数组的字节长度
char str[] = "This is a test.";
int a[10];
double xy[10];
cout << "sizeof(str) = " << sizeof(str) << endl;
cout << "sizeof(a) = " << sizeof(a) << endl;
cout << "sizeof(xy) = " << sizeof(xy) << endl;
cout << endl;
 
//用sizeof 计算自定义类型的长度
struct st {
	short num;
	float math_grade;
	float Chinese_grade;
	float sum_grade;
};
st student1;
cout << "sizeof(st) = " << sizeof(st) << endl;
cout << "sizeof(student1) = " << sizeof(student1) << endl;
 
 
 
 
 
return 0;

}