Thread: A tiny question about memcpy

Hello, I am new to C++.
I know the use of function memcpy().
but what is the difference between using memcpy(&str1, &str2, sizeof(str2)) and str1 = str2 ?

memcpy will copy the contents of an address for n bytes. str1 = str2 will assign the address str2 to str1 (assuming they're pointers).

Originally posted by Enmeduranki
memcpy will copy the contents of an address for n bytes. str1 = str2 will assign the address str2 to str1 (assuming they're pointers).

is memcpy() slower if I want to copy a exact variable ?

>is memcpy() slower if I want to copy a exact variable ?

You're not copying an exact variable by assigning one pointer to another. You're copying a pointer.

Originally posted by Enmeduranki
>is memcpy() slower if I want to copy a exact variable ?

You're not copying an exact variable by assigning one pointer to another. You're copying a pointer.

how if I using * before a pointer ?

If you're only copying sizeof(one primitive) then yes.

Originally posted by Enmeduranki
If you're only copying sizeof(one primitive) then yes.

you mean memcpy() is slower ?

Almost definitely, but it'll be up to the implementation.

Thanks !