小编Cor*_*ory的帖子

使用realloc时内存是否自动释放？或者是否有必要免费使用realloc？以下哪项是正确的？

//Situation A
ptr1 = realloc(ptr1, 3 * sizeof(int));

//Situation B
ptr1 = realloc(ptr2, 3 * sizeof(int));
free(ptr1);
ptr1 = ptr2;

尝试创建一个结构数组(C的新增功能),但是当我尝试初始化数组时,我得到的是"数组类型具有不完整的元素类型".我做错了什么？

typedef struct morsechar
{
   char  character;
   char* morse;
} MorseChar;

struct MorseChar lookup[] ={{'A', ".-"},    {'B', "-..."},  {'C', "-.-."},  
                            {'D', "-.."},   {'E', "."},     {'F', "..-."},      
                            {'G', "--."},   {'H', "...."},  {'I', ".."},
                            {'J', ".---"},  {'K', "-.-"},   {'L', ".-.."},
                            {'M', "--"},    {'N', "-."},    {'O', "---"},
                            {'P', ".--."},  {'Q', "--.-"},  {'R', ".-."},
                            {'S', "..."},   {'T', "-"},     {'U', "..-"},
                            {'V', "...-"},  {'W', ".--"},   {'X', "-..-"},
                            {'Y', "-.--"},  {'Z', "--.."},  {'0', "-----"}, 
                            {'1', ".----"}, {'2', "..---"}, {'3', "...--"},
                            {'4', "....-"}, {'5', "....."}, {'6', "-...."}, …