포인터, 배열, 구조체 연산

[포인터 연산]

(일반 배열)

p[i]

*(p+i)

(구조체 배열)

p[i].idx

*(p+i).idx

(p+i)->idx

소스

/*

 ============================================================================

 Name        : pointer.c

 Author      : 

 Version     :

 Copyright   : 

 Description : pointer in C, Ansi-style

 ============================================================================

 */

#include <stdio.h>

#include <string.h>

struct mystruct{

char str[10];

int ii;

};

int main(void)

{

struct mystruct mystruct;

struct mystruct* pmystruct;

pmystruct=&mystruct;

strcpy(mystruct.str,"test");

mystruct.ii=45;

printf("mystruct.str: %s\n",mystruct.str);

printf("mystruct: %d\n",mystruct.str);

struct mystruct* str = mystruct.str;

printf("str->ii: %d\n",str->ii);

printf("\n");

printf("mystruct.ii: %d\n",mystruct.ii);

printf("pmystruct->ii: %d\n",pmystruct->ii);

printf("pmystruct[0].ii: %d\n",pmystruct[0].ii);

printf("(pmystruct+0)->ii: %d\n",(pmystruct+0)->ii);

printf("\n");

printf("mystruct: %d\n",mystruct);

printf("&mystruct: %d\n",&mystruct);

printf("pmystruct: %d\n",pmystruct);

printf("\n");

int arrint[5]={1,2,3,4,5};

int* parrint = arrint;

printf("arrint: %d\n",arrint);

printf("arrint[0]: %d\n",arrint[0]);

printf("parrint[0]: %d\n",parrint[0]);

printf("*(parrint): %d\n",*(parrint));

printf("*(arrint): %d\n",*(arrint));

return 0;

}

결과

mystruct.str: test

mystruct: 2293600

str->ii: 45

mystruct.ii: 45

pmystruct->ii: 45

pmystruct[0].ii: 45

pmystruct+0.ii: 45

mystruct: 1953719668

&mystruct: 2293600

pmystruct: 2293600

arrint: 2293552

arrint[0]: 1

parrint[0]: 1

*(parrint): 1

*(arrint): 1