Unexpected unsigned integer behavior

Question

I encountered this unexpected output with the following code in which I was verifying the maximum values (represented in decimal form) of the unsigned forms of short and int

Answer 1

Using printf(), your conversions in the format string must match the type of the arguments, otherwise the behavior is undefined. %d is for int.

Try this for the maximum values:

#include <stdio.h>

int main()
{
    printf("Max unsigned int = %u\n", (unsigned)-1);
    printf("Max unsigned short = %hu\n", (unsigned short)-1);
    return 0;
}

---

Side notes:

• the maximum value of any unsigned type is -1 cast to that type.
• Put newline at the end of your lines. Among other reasons, this flushes stdouts buffer with the default setting of line buffered.

Answer 2

You need to use %u for the format specifier for an unsigned type.