06-データ構造_予備知識-クロス関数使用メモリ

#include <stdio.h>
#include <malloc.h>
#include <string.h>
/*
       
1,  A           
2,  A     , B             
  :
1,  createStudent   ,       
2,  printStudent   ,        
*/
struct Student
{
    int id;
    char name[100];
    int age;
};

//        ,        
struct Student * createStudent(void);
//      
void printStudent(struct Student * pSt);

int main(void)
{
    struct Student * pSt = NULL;

    pSt = createStudent();

    printStudent(pSt);

    return 0;
}

struct Student * createStudent()
{
    struct Student * pSt = (struct Student *) malloc( sizeof(struct Student) );
    pSt->id = 123;
    strcpy(pSt->name, "  ");
    pSt->age = 20;
    return pSt;
}

void printStudent(struct Student * pSt)
{
    printf("%d, %s, %d
", pSt->id, pSt->name, pSt->age);
    return;
}