直接上结果

#include <iostream>

using namespace std;

int main() {
    int* A = new int[10];
    int* B = new int[10]();
    for(int i = 0; i < 10; ++i) {
        cout << A[i] << " ";
    }
    cout << endl;
    for(int i = 0; i < 10; ++i) {
        cout << B[i] << " ";
    }
    cout << endl;
    return 0;
}

0 536870912 0 536870912 -957349872 32767 -1114432673 32767 -957337400 32767
0 0 0 0 0 0 0 0 0 0

由结果可知new int[10] 只初始化第一个数为0， new int[10] ()将分配的内存全部初始化为 0