// After delete is called on a pointer, its value is, theoretically,
// indeterminate.  However, in many implementations, the value is simply
// left unchanged.
//
// After a pointer is deleted, the pointer is “stale” or “dangling”.
// Just because you have a pointer to the data, doesn’t mean that
// you are allowed to access the data.  Don’t!

#include <iostream>

using namespace std;

// Show an array of data.  You have to pass the length, because C++ doesn’t
// know the length of a C-style array.

void show(int data[], int length) {
    for (int i=0; i<length; i++)
	cout << data[i] << ' ';
    cout << '\n';
}

int main() {
    constexpr int SIZE = 12;
    int *p = new int[SIZE];

    for (int i=0; i<SIZE; i++)
	p[i] = 1000+i;

    cout << "Before delete: "; show(p, SIZE);	// I expect 1000…1011
    delete[] p;					// Note the []
    cout << "After delete:  "; show(p, SIZE);	// God only knows.

    // delete[] p;				// Give it a try.

    return 0;
}