Re: Please give me a hint!

From:

mzdude <jsanga@cox.net>

Newsgroups:

comp.lang.c++

Date:

Thu, 23 Apr 2009 05:51:56 -0700 (PDT)

Message-ID:

<d1311d9d-9021-4e92-958e-ef75adf39fe5@f19g2000yqo.googlegroups.com>

On Apr 22, 10:51 pm, chuan <chuan...@googlemail.com> wrote:

I am trying to write a class for jackknife algorithm.
I need a dynamic array, which I call jack, inside the class.
Here is my code in jackknife.h

#include <iostream>
#include <vector>
#include <math.h>

class jackknife{
  int bin;
  double* jack;
  double* data;

public:
  jackknife();
  ~jackknife();
  int setbin(int);

};

jackknife::jackknife() {
  bin = 0;

}

jackknife::~jackknife(){
    delete [] jack;

}

int jackknife::setbin(int n) {
  bin = n;
  jack = new double [n];
  return bin;

}

I allocat memory in setbin, then debugger tells me
the program crashes in the deconstructor, when I free the memory.

I have little experience of C++, I realize the memory management must
be wrong.
But how to correct it.

class jackknife {
  std::vector<double> jack;
  std::vector<double> data;

size_t setbin( size_t newSize )
  {
     jack.resize(newSize);
     return newSize;
  }

};

Note that you no longer need to worry about constructors, destructors
or copy operators.