在下面的程式碼片段中：
#include <iostream>
int main(){
unsigned int* wsk2 = new unsigned int(5);
std::cout << "wsk2: " << wsk2 << " " << *wsk2 << std::endl;
delete wsk2;
wsk2 = new unsigned int;
std::cout << "wsk2: " << wsk2 << " " << *wsk2 << std::endl;
return 0;
}預期的結果是記憶體沒有初始化為零，但輸出是：
wsk2: 0x928e008 5 wsk2: 0x928e008 0
看來operator new正在將記憶體初始化為零，但實際上不是。
它是如何運作的：
new 運算子有兩個版本：
wsk = new unsigned int; // default initialized (ie nothing happens) wsk = new unsigned int(); // zero initialized (ie set to 0)
預設值初始化不會初始化內存，而值初始化不會初始化內存，而零初始化則將記憶體設為零。
它也適用於陣列：
wsa = new unsigned int[5]; // default initialized (ie nothing happens) wsa = new unsigned int[5](); // zero initialized (ie all elements set to 0)
要確認記憶體實際上已清除，我們可以將新的版面與已知的記憶體一起使用：
#include <new>
#include <iostream>
int main()
{
unsigned int wsa[5] = {1,2,3,4,5};
// Use placement new (to use a know piece of memory).
// In the way described above.
//
unsigned int* wsp = new (wsa) unsigned int[5]();
std::cout << wsa[0] << "\n"; // If these are zero then it worked as described.
std::cout << wsa[1] << "\n"; // If they contain the numbers 1 - 5 then it failed.
std::cout << wsa[2] << "\n";
std::cout << wsa[3] << "\n";
std::cout << wsa[4] << "\n";
}此程式碼的輸出是：
0 0 0 0 0
這證實了記憶體確實被運算子new的零初始化版本清零了。
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