Looping with an unsigned char

Question

What is an elegant way of executing something similar to this without entering an infinite loop, if i must be an unsigned char?

for (unsigned char i = 0; i < 256; ++i) {
    printf("%d\n", i); 
}   

Answer 1

unsigned char i = 0;
do {
    printf("%u\n",i);
}while(++i != 0);

Do the increment in the loop test and test against the wrapped value.

Answer 2

As a general rule of thumb: if your iterator variable needs to hold all values between 0 and "Uxxx_MAX", you picked a too narrow type for the algorithm.

You should have considered using uint16_t instead.

There are just so many cases where you can't use a large int type instead of your unsigned char. So let me ask you, is your application a real time embedded system, written for an 8-bit MCU, where you have found that this very loop is a performance bottleneck?

• If yes, then write an obscure loop with uint8_t as the type of the iterator, and comment why you did it.
• If no, then use uint16_t or a larger integer type.