Re: Errors

"Tadeusz B. Kopec" <>
12 Nov 2007 21:37:48 +0100
On Sun, 11 Nov 2007 21:46:46 -0800, Latina wrote:

Hi I am doing a program oveloraded operator. I am having a few errors on

Quite many, i would say. First of all, if it's not an exercise someone
gave to you but a class to be used somewhere, you should use
std::set<int> or make a class that's just a wrapper for it. Your class
has many problems.

class IntegerSet
        bool set[26];

First of all, it seems to be a set of integers from range [0..25]. Is it
what you wanted?
Second - it's wasting space. Use std::vector<bool> or if you want a fixed
size - std::bitset.

        int element;

What is this member variable for? The only use I could see is a loop
variable and for that a local variable would do.

       //Operator methods.
       IntegerSet operator + (const IntegerSet &)const;//method union

       IntegerSet(); //default constructor

This comment is useless - doesn't say anything more that code does.

       IntegerSet(int x[], int k); //overload constructor

This comment is also useless. But this constructor needs a comment:
"x - array of integers to add to set
k - size of x
x must not contain numbers greater than 25 nor less then 0".

       bool isValid(int)const;

// It should be rather "contains". There is nothing invalid in not being
kept in a specific set.

       void insertElement(int);
       void deleteElement(int);
       void setString();
       void inputSet();

IntegerSet set();

You declare a function named set. What for? You don't seem to use it.

    for(element=0; element>=25; element++)
        set[element]= false;

The only thing this function does is assigning 0 to element.

IntegerSet::IntegerSet(int x[], int k) {
    for(element=0; element>=25; element++)
        set[element]= false;

Again you assign 0 to element and nothing else;

    for(int j=0; j<k; j++)
            set[element]= true;

If x contains a number greater than 25 or less then 0, you have undefined


bool IntegerSet::isValid(int i)const
     return set[i];

Do you intentionally omit bound checking?

//insert element to a set
void IntegerSet::insertElement(int element) {

// Comments are useful at method declaration not definition. Again you
omit bound checking.

//delete element of a set
void IntegerSet::deleteElement(int element) {


//overloaded operator + to compute the union of two sets IntegerSet
IntegerSet::operator+(const IntegerSet &right)const {
      IntegerSet j;

      for(int element=0; element<=25; element++) {
              if(isValid(element) || right.isValid(element))
      return j;

int main()
  IntegerSet run;
  IntegerSet S1set[26];
  IntegerSet S2set[26];
  IntegerSet S3set[26];
  IntegerSet Sset[26];

  for(int i=2; i< ; i+2)
          S1set.insertElement(); <--Error 1

As Jim Langston noticed S1set is an array. On which element of it would
you like to invoke the method. And when you decide which one, shoudn't
you give an argument?

  for(int k=6; k<=21; k+3)
          S2set.insertElement(); <--Error 1

  for(int j=3; j<=18; j+6)
          S3set.insertElement(); <--Error 1

  for(int z=0; z<=25; z++)
          Sset.insertElement(); <--Error 1

  int choice;

  cout<<"\n WELCOME to the INTEGER SET PROGRAM\n";
  cout<<"\n\nSelect one of these choices\n"; cout<<" 0. Create set
  cout<<" 1. Find Union \n";

       int temp, ele;
       int newSet[26];

       cout<<"Enter how many elements you want in the set: "<<endl;

What if user enters 'Hello world'? And what if '1024'?

       for(int i=0; i<ele; i++)
  else if(choice==1)
       char a, b, c, d, e,;
       int option;

       cout<<"Select one of this choices";
       cout<<"a. To find the union of the set you enter and the set
       cout<<"b. To find the union of the set you enter and the set
       cout<<"c. To find the union of the set you enter and the set
       cout<<"d. To find the union of the set you enter and the set
             run.operator+(Sset); <--Error 2

Again Sset is an array.
Also you haven't done anything with variable run yet. Is it intended? And
the only sense of providing operator+ is to write 'run + Sset[0]' instead
of 'run.operator+(Sset[0])'

       else if(option=='b'||option=='B')
             run.operator+(S1set); <--Error 2
       else if(option=='c'||option=='C')
             run.operator+(S2set); <--Error 2
       else if(option=='d'||option=='D')
             run.operator+(S3set); <--Error 2

  return 0;

I hope some one can help me.

Tadeusz B. Kopec (
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