Try to copy uint8_t number into uint8_t array with memcpy

I’m trying to use memcpyto copy an uint8_t to an uint8_t[] but it’s doesn’t work here is what I’ve tried

uint8_t mess[16];
uint8_t my_number = 1;
memcpy(mess, &my_number, sizeof(my_number)); 

When I print my mess I have nothing

>Solution :

SerialUSB.println(char *)mess)

SerialUSB.println requires a null terminated string, but the below does not initialize the array so the values in the array are indeterminate:

uint8_t mess[16];

Reading indeterminate vales makes the program have undefined behavior so initialize it:

uint8_t mess[16]{}; // now initialized with 0:s

Further, memcpy is unnecessary here:

uint8_t my_number = 1;
memcpy(mess, &my_number, sizeof(my_number)); 

It’s the same as

mess[0] = my_number;

And it’s unlikely that you actually wanted the character with value 1 when using println since it’s an "invisible" character (in ASCII at least), but instead wanted the character '1':

mess[0] = static_cast<uint8_t>('1');