釋放結構體數組里面的指針

//定義如下結構體
typedef struct student
{
    int id;
    char* name;
} student_t;

int main(){

    //有四種定義形式

    //一、結構體變量
    student_t xiaoming; //不需要為結構體分配內存，但是需要對name分配內存
    xiaoming.name =(char*)malloc(10);
    free(xiaoming.name); //釋放成員指針

    //二、結構體指針
    student_t *xiaoming=NULL;
    xiaoming = (student_t*）malloc(sizeof(student_t));
    xiaoming.name =(char*)malloc(10);
    free(xiaoming.name); //釋放成員指針
    free(xiaoming); //釋放指針

    //三、結構體數組
    student_t xiaoming[3];
    for( i = 0; i<3 ; i++ )
    {
      xiaoming[i].name = (char*)malloc(10); //初始化
    }
    for( i = 0; i<3 ; i++ )
    {
      free(xiaoming[i].name); //釋放成員指針
    }
    
    //四、結構體數組（第三種的另一種寫法）
    student_t *xiaoming=NULL;
    xiaoming = (student_t*）malloc(sizeof(student_t)*3);
    for( i = 0; i<3 ; i++ )
    {
      xiaoming[i].name = (char*)malloc(10); //初始化
    }
    for( i = 0; i<3 ; i++ )
    {
      free(xiaoming[i].name); //釋放成員指針
    }
    free(xiaoming); //釋放數組
    
    return 0;
}