优先选择 malloc 而不是 calloc
可能的重复：
malloc 和 calloc 之间的区别
是否存在您更喜欢 malloc 的情况卡洛克。我知道 malloc 和 calloc 都动态分配内存，并且 calloc 还将分配的内存中的所有位初始化为零。 由此我猜想使用 calloc 总是比 malloc 更好。或者在某些情况下 malloc 更好？性能可能是？
Possible Duplicate:
c difference between malloc and calloc
Is there any situation where you would prefer malloc over calloc. i know both malloc and calloc allocate memory dynamically and that calloc also initializes all bits in alloted memory to zero.
From this i would guess its always better to use calloc over malloc. Or is there some situations where malloc is better? Performance may be?
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通常，您分配内存的具体目的是在那里存储某些内容。这意味着（至少大部分）由 calloc 初始化为零的空间很快就会被其他值覆盖。因此，大多数代码使用
malloc来提高一点速度，而不会造成真正的损失。我见过的 calloc 的唯一用途几乎是（据说）对 Java 相对于 C++ 的速度进行基准测试的代码。在 C++ 版本中，它使用 calloc 分配了一些内存，然后使用 memset 再次初始化内存（在我看来）这是一种相当透明的尝试，以产生有利于结果的结果爪哇。
You're normally allocating memory with the specific intent of storing something there. That means (at least most of) the space that's zero-initialized by
callocwill soon be overwritten with other values. As such, most code usesmallocfor a bit of extra speed with no real loss.Nearly the only use I've seen for
callocwas code that was (supposedly) benchmarking the speed of Java relative to C++. In the C++ version, it allocated some memory withcalloc, then usedmemsetto initialize the memory again in (what seemed to me) a fairly transparent attempt at producing results that favored Java.如果您需要对动态分配的内存进行零初始化，请使用
calloc。如果不需要将动态分配的内存进行零初始化，则使用
malloc。您并不总是需要零初始化的内存；如果不需要内存零初始化，则无需支付初始化成本。例如，如果您分配内存，然后立即复制数据以填充分配的内存，则没有任何理由执行零初始化。
calloc和malloc是执行不同操作的函数：使用最适合您需要完成的任务的函数。If you need the dynamically allocated memory to be zero-initialized then use
calloc.If you don't need the dynamically allocated memory to be zero-initialized, then use
malloc.You don't always need zero-initialized memory; if you don't need the memory zero-initialized, don't pay the cost of initializing it. For example, if you allocate memory and then immediately copy data to fill the allocated memory, there's no reason whatsoever to perform zero-initialization.
callocandmallocare functions that do different things: use whichever one is most appropriate for the task you need to accomplish.如果您不小心，依赖 calloc 的零初始化可能会很危险。正如预期的那样，清零内存为整型类型提供 0，为 char 类型提供 \0。但它不一定对应于 float/double 0 或 NULL 指针。
Relying on calloc's zero-initialisation can be dangerous if you're not careful. Zeroing memory gives 0 for integral types and \0 for char types as expected. But it doesn't necessarily correspond to float/double 0 or NULL pointers.