include <stdio.h>

int main() {

printf("Hello, World!\n");
return 0;

}

int age = 20; float salary = 8500.50; char grade = 'A';

// 函数定义 int addNumbers(int a, int b) {

return a + b;

}

// 函数调用 int result = addNumbers(5, 3);

int number = 42; int *ptr = &number; // ptr指向number的地址

struct Student {

char name[50];
int age;
float gpa;

};