c - Why doesn't the compiler warns me about an obvious error?

Question

So, I just studied the Arrays material and got a problem...
I got this following code:

int a[5]; 
int i;
for(i=0; i<=10; i++) {
    scanf("%d", &a[i]);
}

I declared on an array that its length is 5.
Then, I ran a for loop from 0 to 10 that inserts numbers into a[i].
I used this table (which I created) to understand what happened during the execute time:

You see the red arrow? That's where the loop she be stopped, because they a[] cannot get more than 5 values into it. Which mean, that a[6] doesn't exist.
Even though, it keeps asking for numbers, and keeps saving them into the array.

One more thing, I'm currently using Dev C++ compiler.

Does anyone has an idea why is it happening?
Thanks!

Answer 1

C doesn't have any standard on constraint on array index out of bound checking.

That means programs are free to violate the index rule. It is upto the programmers to check the array index constraint.

And, that will result in an undefined behaviour.