背景

A对象内部属性a属于int ，动态分配内存回收，析构函数delete
A ** aptr = new A[10] 申请10个空间长度的A*类型
测试浅拷贝

测试代码

#include<iostream>
using namespace std;
class A{
public:
    int* a;
    A(int i){ //构造函数
        a = new int(i) ;
    }
    ~A(){ //析构函数
        cout<<"~A() i = "<<*(this->a)<<endl;
        if(a!= nullptr){
            delete a;
            a= nullptr;
        }
    }
};

//二级指针的空间申请与分配
void test(){
    int len = 10;
    A ** aptr = new A*[len]; //申请10个空间为A*类型指针空间
    for(int i = 0; i < len; i++){
        aptr[i] = new A(i); //为每个指针申请空间
    }
    //先释放A*
    for (int i = 0; i < len; ++i) {
        delete aptr[i];
    }
    //再释放A**
    delete [] aptr;
}
//指针拷贝
void test_copy_ptrArr(){
    int len = 10;
    A ** aptr = new A*[len]; //申请10个空间为A*类型指针空间
    for(int i = 0; i < len; i++){
        aptr[i] = new A(i); //为每个指针申请空间
    }
    //拷贝（浅拷贝）
    A ** bptr = new A*[len];
    for (int i = 0; i < len; i++) {
        bptr[i] = aptr[i];// 属于浅拷贝
    }
    //打印地址查看
    for (int i = 0; i < len; ++i) {
        cout<<"aptr["<<i<<"] = "<<aptr[i]<<endl;
        cout<<"bptr["<<i<<"] = "<<bptr[i]<<endl; //两者打印的是一样
    }
//    delete[] aptr; //释放的是aptr,*aptr没有释放,可能会出现内存溢出
//    for (int i = 0; i < len; ++i) {
//        cout<<"aptr["<<i<<"] = "<<*(aptr[i]->a)<<endl;
//        cout<<"bptr["<<i<<"] = "<<*(bptr[i]->a)<<endl;
//    }
    //完整释放(拷贝后释放)
    for (int i = 0; i < len; ++i) {
        delete bptr[i]; // 会调用~A()析构函数
    }
    delete[] bptr;
    delete[] aptr;
}
int main()
{
//    test();
    test_copy_ptrArr();
    return 0;
}