What is the proper method for modifying char array?

[blh64]

@winner10920

    if (UniqueID[i] < 0x10) num[i*2] = '0';

    sprintf(buf,"%X",UniqueID[i]);

    num[i*2] = buf[0];

    if(UniqueID[i] > 0x10) num[(i*2)+1] = buf[1];

What happens when UnidqueID[i] == 0x10? This code does not handle that case. Better to just let sprintf() handle it correctly

    sprintf(buf,"%02X",UniqueID[i]);
    num[i*2] = buf[0];
    num[i*2+1] = buf[1];