What’s the runtime behavior of below code piece?（单选）
int *p = (int *)malloc(sizeof(int));
p = NULL;
free(p);
[不定项选择题]
好棒
个人理解：
int *p = (int *)malloc(sizeof(int)); // p指向申请到的内存
p = NULL; //p指向NULL，之前指向的内存就无法释放了；内存泄漏
free(p);
p = NULL; //p指向NULL，之前指向的内存就无法释放了；内存泄漏
free(p);
发表于 2020-09-01 20:33:10
回复(0)
应该先进行free(p),然后P=Null,防止野指针。 第二行，p=null，那么第一行的空间就丢失了，没法释放
发表于 2022-09-13 09:48:34
回复(1)
man 3 free用法，是这样说的：
"The free() function frees the memory space pointed to by ptr, which must have been returned by a previous call to malloc(), calloc() or realloc(). Otherwise, or if free(ptr) has already been called before, undefined behavior occurs. If ptr is NULL, no operation is performed."
"The free() function frees the memory space pointed to by ptr, which must have been returned by a previous call to malloc(), calloc() or realloc(). Otherwise, or if free(ptr) has already been called before, undefined behavior occurs. If ptr is NULL, no operation is performed."
发表于 2023-04-26 13:55:39
回复(0)
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