Question

\(\mathrm{C}++\) has no array _________ checking, which means you can inadvertently store data past the end of an array.

Short answer

Answer: In C++ array handling, the issue is that there is no array boundary checking. It means you can inadvertently store or access data past the end of an array without getting any errors during compilation. Here's an example illustrating the problem: ```cpp #include using namespace std; int main() { int numbers[5] = {1,2,3,4,5}; // Attempt to store a value beyond the array boundary numbers[5] = 6; // undefined behavior as valid indexes are 0 to 4 only // Attempt to access data beyond the array boundary int value = numbers[10]; // undefined behavior as valid indexes are 0 to 4 only return 0; } ``` In this example, we store a value at an invalid index (5) and access data from an invalid index (10) for the numbers array. Since C++ doesn't perform array boundary checking, it doesn't throw an error during compilation, but can potentially lead to undefined behavior, crashes, or data corruption during runtime.

Step-by-step solution

Identify the missing term

The missing term in the given exercise is "boundary". So the complete statement should be: "C++ has no array boundary checking, which means you can inadvertently store data past the end of an array."

Explain array boundary checking

Array boundary checking is a programming feature that ensures the access to an array stays within its valid index range. If an attempt is made to store or access data beyond the range, an exception/error is thrown. However, C++ does not provide built-in functionality to check array boundaries during runtime. This can lead to potentially accessing/overwriting memory outside the array, causing undefined behavior or even crashes.

Provide an example illustrating the problem

Let's consider an example where array boundary checking is not performed in C++, which can cause an issue: ```cpp #include using namespace std; int main() { int numbers[5] = {1,2,3,4,5}; // Attempt to store a value beyond the array boundary numbers[5] = 6; // undefined behavior as valid indexes are 0 to 4 only // Attempt to access data beyond the array boundary int value = numbers[10]; // undefined behavior as valid indexes are 0 to 4 only return 0; } ``` In the above code, we first attempt to store a value at the index 5, which is outside the valid index range of the numbers array [0, 4]. Next, we try to access data from index 10, which also doesn't exist in the numbers array. Since C++ doesn't perform array boundary checking, neither of these operations will result in an error during compilation. However, they can potentially lead to undefined behavior, crashes, or data corruption during runtime.