spreadsheetcell.cpp

C++高级编程这本书所附的源代码

#include "SpreadsheetCell.h"

#include <iostream>
#include <sstream>
using namespace std;

SpreadsheetCell::SpreadsheetCell() : mValue(0), mNumAccesses(0)
{
}

SpreadsheetCell::SpreadsheetCell(double initialValue) : mNumAccesses(0)
{
  set(initialValue);
}

SpreadsheetCell::SpreadsheetCell(const string& initialValue) :
  mValue(stringToDouble(initialValue)), mString(initialValue), mNumAccesses(0)
{
}

SpreadsheetCell::SpreadsheetCell(const SpreadsheetCell& src)
{
  mValue = src.mValue;
  mString = src.mString;
  mNumAccesses = src.mNumAccesses;
}

SpreadsheetCell& SpreadsheetCell::operator=(const SpreadsheetCell& rhs)
{
  if (this == &rhs) {
    return (*this);
  }
  mValue = rhs.mValue;
  mString = rhs.mString;
  mNumAccesses = rhs.mNumAccesses;
  return (*this);
}

void SpreadsheetCell::set(double inValue)
{
  mValue = inValue;
  mString = doubleToString(mValue);
}

void SpreadsheetCell::set(const string& inString)
{
  mString = inString;
  mValue = stringToDouble(mString);
}

string SpreadsheetCell::doubleToString(double inValue)
{
  ostringstream ostr;

  ostr << inValue;
  return (ostr.str());
}

double SpreadsheetCell::stringToDouble(const string& inString)
{
  double temp;

  istringstream istr(inString);

  istr >> temp;
  if (istr.fail() || !istr.eof()) {
    return (0);
  }
  return (temp);
}

const SpreadsheetCell SpreadsheetCell::operator+(
    const SpreadsheetCell& cell) const
{
  SpreadsheetCell newCell;
  newCell.set(mValue + cell.mValue); // call set to update mValue and mString
  return (newCell);
}