c - malloc和calloc之间的区别？(Difference between malloc and calloc?)

Question

What is the difference between doing:

(做的有什么区别：)

ptr = (char **) malloc (MAXELEMS * sizeof(char *));

or:

(要么：)

ptr = (char **) calloc (MAXELEMS, sizeof(char*));

When is it a good idea to use calloc over malloc or vice versa?

(什么时候使用calloc而不是malloc是一个好主意，反之亦然？)

  ask by user105033 translate from so

Answer 1

calloc() zero-initializes the buffer, while malloc() leaves the memory uninitialized.

(calloc()将初始化缓冲区，而malloc()使内存未初始化。)

EDIT:

(编辑：)

Zeroing out the memory may take a little time, so you probably want to use malloc() if that performance is an issue.

(将内存清零可能需要一些时间，因此如果性能问题，您可能希望使用malloc() 。)

If initializing the memory is more important, use calloc() .

(如果初始化内存更重要，请使用calloc() 。)

For example, calloc() might save you a call to memset() .

(例如， calloc()可能会保存对memset()的调用。)