struct pointer.cpp

struct pointer.cpp

#include <stdio.h>

struct data {
	int a;
};

typedef struct data2 {
    int aa;
} hello; //以後不用打struct data2，直接叫他hello就好了!!

void foo(struct data* ptr)
{
    printf("ptr holds value %p.\n", ptr);
    ptr->a = 2;
    printf("value changed to 2\n\n");
}

int main()
{
	struct data var;
	var.a = 1;

	printf("var address is %p.\nvar.a is %d\n\n", &var, var.a);

    foo(&var);

    printf("var address is %p.\nvar.a is %d\n\n", &var, var.a);

    // ==================

    hello newVar;
    newVar.aa = 2000;
    printf("newVar.a is %d\n", newVar.aa);

	return 0;
}