Consider the following code:
#include <iostream> using namespace std; int main(){ int* p = new int[2]; for (int i = 0; i < 2; i++) cout << p[i] << endl; return 0; } I run it several times. It always produces the following output:
0 0 Can I assume that C++ default-initialization set array elements to its default value? In this case, can I assume that p's element values are always set to 0?
I have read the following related questions. But they does not specifically address my case:
Can I assume that C++ default-initialization set array elements to its default value?
No, for default initialization:
- if T is an array type, every element of the array is default-initialized;
and the element type is int, then
- otherwise, nothing is done: the objects with automatic storage duration (and their subobjects) are initialized to indeterminate values.
On the other hand, list initialization(since C++11) like int* p = new int[2]{}; or int* p = new int[2]{0};, or value initialization like int* p = new int[2](); will guarantee that, for int all the elements will be zero-initialized.
