What happen when give value bigger than CHAR_MAX (127) to char

Asked Feb 21 '18 at 09:32

Active Feb 21 '18 at 13:48

Viewed 86 times

char* c = new char[1];
c = { 128 };

When I using Qt debugger to display the contains of c , it shows 128.

So tried another way:

c = 128;

also shows 128 in the debugger.

What happens in memory when assigning a value which bigger than the maximum range.

edited Feb 21 '18 at 13:48

klutt

asked Feb 21 '18 at 09:32

JustWe

4

Undefined behaviour because it's a signed overflow – UKMonkey Feb 21 '18 at 09:34
5

It depends. If `char` is signed then overflowing it will lead to *undefined behavior*. If `char` is unsigned, then that's okay. If a `char` is signed or unsigned is "implementation specified", i.e. it's up to the compiler. – Some programmer dude Feb 21 '18 at 09:34
Please! No more! – Martin James Feb 21 '18 at 10:18
@martin It seems you are in agony. Take it easy :) – machine_1 Feb 21 '18 at 10:24
2

@Someprogrammerdude & UKMonkey this is not signed overflow. Converting a non-representable value to a signed integer results in implementation defined value; not UB. Overflow happens during arithmetic operations. – eerorika Feb 21 '18 at 10:38

0 Answers0