The memset() function copies the low-order byte of ch into the first count characters of the array pointed to by buf. It returns buf.
The most common use of memset() is to initialize a region of memory to some known value.
Following is the syntax of the memset() function :
#include<string.h> void *memset(void *buf, int ch, size_t count);
Following code fragment initializes to null the first 100 bytes of the array pointed to by buf. Then it sets the first 10 bytes to X and displays the string XXXXXXXXXX.
memset(buf, '\0', 100); memset(buf, 'X', 10); printf(buf);