My own vector class - c++

Question

I am trying to create my own vector class. I want to overload the basic features of STL vector. My code is compiling by after testing it, a message "segmentation fault(core dumped is)" is shown. Could you show me where I can improve my code. Thank you in advance!
#include<iostream>
#include<fstream>
using namespace std;
class Vector
{
public:
Vector();
Vector(const Vector& vect);
~Vector();
Vector& operator =(const Vector& vect);
void insert(double element);
bool operator ==(const Vector& vect);
Vector& operator +(const Vector& vect);
Vector& operator -(const Vector& vect);
Vector& operator *(const Vector& vect);
int size();
double operator[](int num);
friend istream& operator >>(istream& input, Vector& vect);
friend ostream& operator <<(ostream& output, Vector& vect);
private:
double* data;
int num;
int max;
};
Vector:: Vector()
{
double* data = NULL;
int num = 0;
int max = 0;
}
Vector::Vector(const Vector& vect)// not sure if its correct
{
data = new double[vect.max];
memcpy(data, vect.data, sizeof(double) * vect.num);
num = vect.num;
max = vect.max;
}
Vector::~Vector()
{
if(data)
{
delete[] data;
data = 0;
}
}
void Vector:: insert(double element)
{
if(num < max)
{
*(data + num) = element;
}
else
{
double *tmp = new double[num * 2];
delete[] data;
*(data + num) = element;
max *= 2;
}
num++;
}
Vector& Vector:: operator = (const Vector& vect)// highly unlikely to be correct
{
if(this != &vect)
{
if(data)
{
delete[] data;
data = 0;
}
max = vect.max;
data = new double[max];
for(int i = 0; i < num; i++)
{
this->data[i] = vect.data[i];
}
}
return *this;
}
bool Vector:: operator ==(const Vector& vect)
{
bool isEqual = true;
if(this->num != vect.num)
{
isEqual = false;
}
for(int i = 0; i < num; i++)
{
if(this->data[i] != vect.data[i] )
{
isEqual = false;
}
}
return isEqual;
}
Vector& Vector:: operator +(const Vector& vect)
{
Vector result;
for (int i = 0; i < num; ++i)
{
result.insert(*(data + i) + *(vect.data + i));
}
return result;
}
Vector& Vector:: operator -(const Vector& vect)
{
Vector result;
for (int i = 0; i < num; ++i)
{
result.insert(*(data + i) - *(vect.data + i));
}
return result;
}
Vector& Vector::operator*(const Vector &vect)
{
Vector result;
for (int i = 0; i < num; ++i)
{
result.insert(*(data + i) * *(vect.data + i));
}
return result;
}
int Vector:: size()
{
return num;
}
double Vector::operator[](int num)
{
return *(data + num);
}
ostream &operator <<(ostream &output, Vector &vect)
{
output << "[";
for (int i = 0; i < vect.size(); ++i)
{
output << vect[i];
if (i < vect.size() - 1)
output << ",";
}
output << "]\n";
return output;
}
istream &operator >>(istream &input, Vector &vect)
{
double element;
input >> element;
vect.insert(element);
return input;
}
int main()
{
Vector vec;
for (int i = 0; i < 10; ++i)
{
vec.insert(i);
}
return 0;
}

Answer 1

Look closely at your insert function. Specifically at how you are re-sizing the array.