char *_strncat(char *dest, char *src, int n)
{
    char *ret = dest;
    while (*dest) /* same as: while (dest[0] !- '') */
    {
        dest++; /* w. each loop, array is shifted left until it's empty */
    }
    while (n != 0)
    {
         if (!(*dest++ = *src++)) /* <=========here */
            return ret;
        n--;
    }
    *dest = 0;
    return (ret);
}

if (!(*dest++ = *src++))
    return;

char temp1 = *src++; // copy from *src to temp1 and increment src
char temp2 = (*dest++ = temp1) // Copy temp1 to *dest, increment dest, and also copy value to temp2
if (!temp2) return ret; // return if the value that was copied is a null byte