Student[] arr = students.stream().filter(a -> a.getHeight() > 170).toArray(len -> new Student[len]);解释一下这段代码

这段代码使用 Java 8 中的 Stream API，从一个名为 students 的 Student 类型的集合中筛选出身高大于 170 的学生，并将结果存储在一个名为 arr 的 Student 类型数组中。具体来说，filter() 方法用于筛选符合条件的元素，toArray() 方法用于将 Stream 转换为数组，len -> new Student[len] 表示创建一个长度为 len 的 Student 类型数组。

相关问题

帮我检查下这段代码哪里有问题：// #pragma once #include<iostream> using namespace std; template<class T> class Myarray { public: Myarray(int Capa) { cout << "M的有残调用" << endl; this->m_Capay = Capa; this->m_size = 0; this->pAdress = new T[this->m_Capay] } Myarray(const Myarray& arr) { cout << "M的拷贝调用" << endl; this->m_Capay = arr.m_Capay; this->m_size = arr.m_Capay; //this->pAdress = arr.pAdress; this->pAdress = new T[arr.m_Capay]; for (int i = 0; i < this->m_size; i++) { this->pAdress[i] = arr.pAdress[i]; } } Myarray& operator=(const Myarray& arr) { cout << "M的有operat用" << endl; if (this->pAdress != NULL) { delete[] this->pAdress; this->pAdress = NULL; this->m_Capay = 0; this->m_size = 0 } this->m_Capay = arr.m_Capay; this->m_size = arr.m_size; this->pAdress = new T[arr.m_Capay]; for (int i = 0; i < m_size; i++) { this->pAdress[i] = arr.pAdress[i]; } return *this; } ~Myarray() { if (this->pAdress != NULL) { cout << "M的西沟调用" << endl; delete[] this->pAdress; this->pAdress = NULL; } } private: T* pAdress; int m_Capay; int m_size; };

在第13行，构造函数的语句 `this->pAdress = new T[this->m_Capay]` 末尾缺少分号`;`，应该修改为：

this->pAdress = new T[this->m_Capay];

在第27行，赋值运算符的语句 `this->m_size = arr.m_Capay;` 应该修改为：

this->m_size = arr.m_size;

在第34行，赋值运算符的语句 `this->m_size = arr.m_size;` 应该修改为：

this->m_size = arr.m_size;

在第38行，析构函数的语句 `this->m_size = 0` 末尾缺少分号`;`，应该修改为：

this->m_size = 0;

修改后的代码如下：

#pragma once
#include<iostream>
using namespace std;

template<class T>
class Myarray {
public:
    Myarray(int Capa) {
        cout << "M的有残调用" << endl;
        this->m_Capay = Capa;
        this->m_size = 0;
        this->pAdress = new T[this->m_Capay];
    }
    Myarray(const Myarray& arr) {
        cout << "M的拷贝调用" << endl;
        this->m_Capay = arr.m_Capay;
        this->m_size = arr.m_size;
        //this->pAdress = arr.pAdress;
        this->pAdress = new T[arr.m_Capay];
        for (int i = 0; i < this->m_size; i++)
        {
            this->pAdress[i] = arr.pAdress[i];
        }
    }
    Myarray& operator=(const Myarray& arr) {
        cout << "M的有operat用" << endl;
        if (this->pAdress != NULL)
        {
            delete[] this->pAdress;
            this->pAdress = NULL;
            this->m_Capay = 0;
            this->m_size = 0;
        }
        this->m_Capay = arr.m_Capay;
        this->m_size = arr.m_size;
        this->pAdress = new T[arr.m_Capay];
        for (int i = 0; i < m_size; i++)
        {
            this->pAdress[i] = arr.pAdress[i];
        }
        return *this;
    }
    ~Myarray() {
        if (this->pAdress != NULL)
        {
            cout << "M的西沟调用" << endl;
            delete[] this->pAdress;
            this->pAdress = NULL;
        }
    }
private:
    T* pAdress;
    int m_Capay;
    int m_size;
};

#pragma once #include<iostream> using namespace std; template<class T> class MyArray { public: // 有参构造 MyAddress(int capacity) { this->m_Capacity = capacity; this->m_Size = 0; this->pAddress = new T[this->m_Capacity]; } // 析构函数 ~MyArray() { if (this->pAddress != NULL) { delete[]this->pAddress; this->MyAddress = NULL; } } // 拷贝构造 MyArray(const MyArray& arr) { this->m_Capacity = arr.m_Capacity; this->m_Size = arr.m_Size; /*this->pAddress = arr.pAddress;*/// 浅拷贝 this->pAddress = new T[arr.m_Capacity];// 深拷贝 // 将arr中的数据都拷贝过来 for (int i = 0; i < this->m_Size; i++) { this->pAddress[i] = arr.pAddress[i]; } } // operator= 防止浅拷贝问题 MyArray& operator=(const MyArray& arr) { // 判断原来堆区是否有数据，如果有先释放 if (this->pAddress != NULL) { delete[]this->pAddress; this->pAddress = NULL; this->m_Capacity = 0; this->m_Size = 0; } // 深拷贝 this->m_Capacity = arr.m_Capacity; this->m_Size = arr.m_Size; this->pAddress=new T[arr.m_Capacity] for (int i = 0; i < this->m_Size; i++) { this->pAddress[i] = arr.pAddress[i]; } return *this; } private: T* pAddress;// 指针指向堆区开辟的真实数组 int m_Capacity;// 数组容量 int m_Size;//数组大小 };上述代码有什么问题？

在上述代码中，`MyArray` 类中的构造函数被命名为 `MyAddress`，而不是 `MyArray`，这是一个拼写错误。

此外，在析构函数中，将 `this->MyAddress` 设置为 `NULL` 是错误的，应该是将 `this->pAddress` 设置为 `NULL` 来释放堆内存。

在赋值操作符重载函数中，没有为 `pAddress` 分配新的内存空间之前就进行了赋值操作，这会导致潜在的内存泄漏。应该先为 `pAddress` 分配新的内存空间，然后再进行赋值操作。

修正后的代码如下：

#pragma once
#include<iostream>
using namespace std;

template<class T>
class MyArray {
public:
    // 有参构造
    MyArray(int capacity) {
        this->m_Capacity = capacity;
        this->m_Size = 0;
        this->pAddress = new T[this->m_Capacity];
    }

    // 析构函数
    ~MyArray() {
        if (this->pAddress != NULL) {
            delete[] this->pAddress;
            this->pAddress = NULL;
        }
    }

    // 拷贝构造
    MyArray(const MyArray& arr) {
        this->m_Capacity = arr.m_Capacity;
        this->m_Size = arr.m_Size;
        this->pAddress = new T[arr.m_Capacity];
        // 将arr中的数据都拷贝过来
        for (int i = 0; i < this->m_Size; i++) {
            this->pAddress[i] = arr.pAddress[i];
        }
    }

    // operator= 防止浅拷贝问题
    MyArray& operator=(const MyArray& arr) {
        // 判断原来堆区是否有数据，如果有先释放
        if (this->pAddress != NULL) {
            delete[] this->pAddress;
            this->pAddress = NULL;
            this->m_Capacity = 0;
            this->m_Size = 0;
        }
        // 深拷贝
        this->m_Capacity = arr.m_Capacity;
        this->m_Size = arr.m_Size;
        this->pAddress = new T[arr.m_Capacity];
        for (int i = 0; i < this->m_Size; i++) {
            this->pAddress[i] = arr.pAddress[i];
        }
        return *this;
    }

private:
    T* pAddress;    // 指针指向堆区开辟的真实数组
    int m_Capacity; // 数组容量
    int m_Size;     // 数组大小
};

修正后的代码中，`MyArray` 类的构造函数被改回为 `MyArray`，修复了拼写错误。同时，在析构函数和赋值操作符重载函数中，修正了错误的内存释放和深拷贝实现。