arr3没有输出 如何解决

Question

 
#include<iostream>
#include<string>
#include<new>
#include <algorithm>
#include <vector>
 
using namespace std;
class myarray{
    public:
        myarray();
        myarray(const myarray&m);
        myarray(int len);
        // myarray add(const myarray& a,const myarray& b);
    ~myarray();
    void setdata(int index,double data);
    double getdata(int index);
     double getlen()const;
    int result[];
    double* e;
    
    myarray &operator =(const myarray&);
    int &operator[](int i)const;
    myarray &operator+(const myarray & ma);
    friend ostream & operator << (ostream & os,const myarray & ma);
    friend istream & operator >> (istream & is,const myarray & ma);
    private:
    int len;
    int *space;
};
myarray::myarray(){this->len = 0;this->space = NULL;
}
myarray::myarray(int len)
{
if (len <= 0) {
 this->len = 0; return; }
 else{
this->len = len;
this->space = new int[this->len];
    }
}
myarray::~myarray(){
    if((this->space)!= NULL){
        delete this->space;
        this->space=NULL;
        len = 0;
    }
}
void myarray::setdata(int index,double data){
    if(this->space != NULL){this->space[index]=data;
    }
};
double myarray::getdata(int index){
    return this->space[index];
};
double myarray::getlen()const {return this->len;};
 
myarray& myarray::operator =(const myarray & m){
 
if (this == &m) { return *this; }
if (this->space != NULL){
delete[] this->space;
this->space = NULL;
}
}
int & myarray::operator [](int i)const {return this->space[i];}
 
ostream & operator << (ostream & os,const myarray & ma){
    for (int i=0;i<ma.getlen();i++){
        os<<ma[i]<<"\t";
        
    }
    return os;
} 
 
istream & operator >>(istream & is,myarray & ma){
    cout <<"输入"<<ma.getlen()<<"个数"<<endl;
    for (int i=0;i<ma.getlen();i++){is>>ma[i];
    } 
    return is;
}
 
 
myarray &myarray::operator+(const myarray &ma)
{
   myarray *t = new myarray(ma.getlen());
   for (int i = 0; i < ma.getlen(); ++i) 
   {
      t->space[i] = space[i] + ma[i]; 
   }
   return *t; 
}
 
 
 
 
int main(){
    int buff;
    cin>>buff;
    myarray arr1(buff);
    myarray arr2(buff);
    cin>>arr1;
    cin>>arr2;
    cout<<"arr2:"<<arr2<<endl;
    myarray arr3 = arr1 + arr2;
    cout<<"arr1+arr2="<<arr3<<endl;
} 

```

Answer 1

没有验证，仅供参考

```c++
#include <iostream>
using namespace std;

class myarray {
public:
    myarray();
    myarray(const myarray& m);
    myarray(int len);
    ~myarray();
    void setdata(int index, double data);
    double getdata(int index);
    double getlen() const;
    myarray& operator=(const myarray& m);
    int& operator[](int i) const;
    myarray& operator+(const myarray& ma);
    friend ostream& operator<<(ostream& os, const myarray& ma);
    friend istream& operator>>(istream& is, myarray& ma);

private:
    int len;
    int* space;
};

myarray::myarray() {
    len = 0;
    space = nullptr;
}

myarray::myarray(int len) {
    if (len <= 0) {
        this->len = 0;
        this->space = nullptr;
    }
    else {
        this->len = len;
        this->space = new int[this->len];
    }
}

myarray::myarray(const myarray& m) {
    len = m.len;
    space = new int[len];
    for (int i = 0; i < len; i++) {
        space[i] = m.space[i];
    }
}

myarray::~myarray() {
    if (space != nullptr) {
        delete[] space;
        space = nullptr;
        len = 0;
    }
}

void myarray::setdata(int index, double data) {
    if (space != nullptr) {
        space[index] = data;
    }
}

double myarray::getdata(int index) {
    return space[index];
}

double myarray::getlen() const {
    return len;
}

myarray& myarray::operator=(const myarray& m) {
    if (this == &m) {
        return *this;
    }
    if (space != nullptr) {
        delete[] space;
        space = nullptr;
    }
    len = m.len;
    space = new int[len];
    for (int i = 0; i < len; i++) {
        space[i] = m.space[i];
    }
    return *this;
}

int& myarray::operator[](int i) const {
    return space[i];
}

ostream& operator<<(ostream& os, const myarray& ma) {
    for (int i = 0; i < ma.len; i++) {
        os << ma.space[i] << "\t";
    }
    return os;
}

istream& operator>>(istream& is, myarray& ma) {
    cout << "Enter " << ma.len << " numbers" << endl;
    for (int i = 0; i < ma.len; i++) {
        is >> ma.space[i];
    }
    return is;
}

myarray& myarray::operator+(const myarray& ma) {
    myarray* t = new myarray(ma.len);
    for (int i = 0; i < ma.len; ++i) {
        t->space[i] = space[i] + ma.space[i];
    }
    return *t;
}

int main() {
    int buff;
    cin >> buff;
    myarray arr1(buff);
    myarray arr2(buff);
    cin >> arr1;
    cin >> arr2;
    cout << "arr2: " << arr2 << endl;
    myarray arr3 = arr1 + arr2;
    cout << "arr1 + arr2 = " << arr3 << endl;
}

```