问题
I am studying the memset function now, but all the examples are regarding to char array as following:
char a[100];
memset(a, 0, 100);
it will set every element in this char array to 0.
I wondered if memset can apply to int array or float array?
回答1:
Yes, it can apply to any memory buffer, but you must input the correct memory buffer size ... memset treats any memory buffer as a series of bytes, so whether it's char, int, float, double, etc, doesn't really matter. Keep in mind though that it will not set multi-byte types to a specific non-zero value ... for example:
int a[100];
memset(a, 1, sizeof(a));
will not set each member of a to the value 1 ... rather it will set every byte in the memory buffer taken up by a to 1, which means every four-byte int will be set to the value 0x01010101, which is not the same as 0x00000001
回答2:
For static-sized and variable-length arrays, you can just
<arbitrary-type> foo [...];
memset (foo, 0, sizeof (foo)); // sizeof() gives size of entity in bytes
Rule of thumb: Never hardcode [data sizes].
(This does not work if you pass arrays as function arguments: Behaviour of Sizeof in C )
回答3:
It can be applied to any array. The 100 at the end is the size in bytes, so a integer would be 4 bytes each, so it would be -
int a[100];
memset(a, 0, sizeof(a)); //sizeof(a) equals 400 bytes in this instance
Get it? :)
来源：https://stackoverflow.com/questions/6816431/memset-function-in-c-language