A strange result occured in the following code(why input result 'b')

Question

int main(void)
    {
       int array[] = {1,2,3,4,5,6,7};
       int i = -1;
       if(i <= (sizeof(array)/sizeof(array[0])) -2)
           printf("a\n");
       else
           printf("b\n");
       return(0);    
    }

I don't know why the IF expression is false.

explained here: http://stackoverflow.com/questions/50605/signed-to-unsigned-conversion-in-c-is-it-always-safe — , Oct 12 '14 at 14:25

2501 · Accepted Answer · 2014-10-12T15:05:28.537

0

You are trying to compare a signed integer int and an unsigned integer size_t. Following C integer promotion rules, i gets promoted to an unsigned integer and therefore wraps to a very large number. When you compare that to the small value on the right side, the result is false.

edited Oct 12 '14 at 15:05

answered Oct 12 '14 at 14:21

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A strange result occured in the following code(why input result 'b')

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