Char array can hold more than expected

Question

I tried to run this code in C and expected runtime error but actually it ran without errors. Can you tell me the reason of why this happens?

char str[10];
sc         


        

Answer 1

This is a good question. And the answer
is that it there is indeed a memory problem
The string is read and stored from the address of str
up until the length of the actual read string demands,
and it exceeds the place you allocated for it.

Now, it may be not crash immediately, or even ever for
short programs, but it's very likely that when you expand
the program, and define other variables, this string will
overrun them, creating weird bugs of all kinds, and it may
eventually also crash.

In short, this is a real error, but it's not uncommon to have
memory bugs like this one which do not affect at first, but
do create bugs or crash the program later.