int a[10];
std::cin >> a[12];
std::cout << a[12];
Shouldn't the a[12] line raise an error as the array is only declared for 10 indexes? Is there something obvious I'm missing, or has it always been like this?
Asked
Active
Viewed 145 times
0
Mayur Mohan
- 19
- 7
-
It's been like this since the earliest days of C. – chris Aug 17 '14 at 14:13
1 Answers
3
You are free to index out of range, but it is undefined behavior. This could eventually manifest in memory stomping, a write access error, or other.
Cory Kramer
- 114,268
- 16
- 167
- 218
-
So is there a way to restrict input if index is more that that declared, without manually checking if the index location is more than the max defined index? – Mayur Mohan Aug 17 '14 at 14:13
-
@MayurMohan, Use `std::array` and its `at` member function, or check the index against the size if you actually plan on it going over sometime. – chris Aug 17 '14 at 14:14