Why can I operate with int > +32767?

Question

I can read that int range (signed) is from [−32767, +32767] but I can say, for example

int a=70000;
int b=71000;
int c=a+b;

printf("%i", c);
return 0;

And the output is 141000 (correct). Should not the debugger tell me "this operation is out of range" or something similar?

I suppose that this has to be with me ignoring the basics of C programming, but none of the books that I'm currently reading tell nothing about this "issue".

EDIT: 2147483647 seems to be the upper limit, thank you. If a sum exceeds that number, the result is negative, wich is expected, BUT if it is a subtraction, for example: 2147483649-2147483647=2 the result is still good. I mean, why the value 2147483649 is correctly hold for that substraction purpose (or at least it seems to me)?

Answer 1

You have misunderstood. The standard guarantees that a int holds [-32767, +32767], but it is permitted to hold more. (In particular, nearly every compiler you are likely to use allows a range [-2147483648, 2147483647]).

There is another problem. If you make the value you assign to a and b bigger you still probably won't get any warning or error. Integer overflow causes "undefined behaviour", and literally anything is allowed to happen.