Insert method overloading - c++

Question

I am trying to overload Insert() method in C++. Here is my code which i had come up with
Below is my List.h file
#ifndef _LIST_H_
#define _LIST_H__
#include "stdafx.h"
#include <cstdlib>
#include <iostream>
class List
{
public:
List(size_t capacity = 5); // constructor - allocates dynamic array
~List(); // destructor
void insert(size_t position, int value);
void printArray();//Printing Array elements
private:
void resize(size_t new_size); // allocate new larger array
int *data_; // dynamic array
size_t size_; // size of dynamic array
size_t capacity_; // capacity of dynamic array
};
inline int& List::operator [] (size_t pos)
{
if (pos >= 0 && pos <= size_ - 1)
{
return data_[pos];
}
}
#endif _LIST_H_
This is my List.cpp file
#include "stdafx.h"
#include "List.h"
#include <iostream>
using namespace std;
List::List(size_t capacity)
{
data_ = new int[capacity];
capacity_ = capacity;
size_ = 0;
}
List::~List()
{
cout << "delete ";
delete[] data_;
}
void List::insert(size_t position, int value) {
if (size_ == capacity_)
{
resize(2 * capacity_);
}
if (position >= 0 && position <= capacity_ - 1)
{
data_[position] = value;
size_++;
}
}
void List::printArray()
{
size_t i;
for (i = 0; i < size_; i++)
{
cout << data_[i]<<" ";
}
}
void List::resize(size_t new_size)
{
int * temp;
size_t i;
capacity_ = new_size;
temp = new int[capacity_];
for (i = 0; i <= size_; ++i)
{
temp[i] = data_[i];
}
delete[] data_;
data_ = temp;
}
main method file
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
//List d,a;
List *arr,*temp;
arr = new List(10);
temp = new List();
arr->insert(1, 3);
cout << "Printing array list after inserting: " << endl;
arr->printArray();
}
Output:
Testing Insert method:
Printing array list after inserting:
-842150451
Expected:
Testing Insert method:
Printing array list after inserting:
3
suppose if i have array like arr =[1,2,3,4]; arr->insert(2,-2). Output should be arr= [1,2,-2,3,4]
Can any one tell me why it is displaying a random number instead of inserted value and How to modify the code

Answer 1

You should change this line:
arr->insert(1, 3);
into:
arr->insert(0, 3);