Memset In C Using Sizeof Operator : -

here struct :

typedef struct tag_device_sys {     char device[string_size];     int id;     char category; } device_sys;

for memset, 1 should used below ?

memset(dev_sys, 0, (size_t)num_devices * sizeof(device_sys));

memset(dev_sys, 0, (size_t)num_devices * sizeof(dev_sys));

what differences ?

i use objects arguments sizeof

struct whatever *ptr; /* ... */ ptr = malloc(nelems * sizeof *ptr); memset(ptr, 0, nelems * sizeof *ptr);

the advantage on using parenthesized type code needs changed @ 1 place should type of data change

struct before_change *ptr; /* ... */ ptr = malloc(nelems * sizeof (struct before_change)); memset(ptr, 0, nelems * sizeof (struct before_change));

Score