Silly Class Question

How do you create a class where the base object can be assigned a value?

I'd like to do something like:

Code:

---

class number{
  public:
  blah blah blah

  void increment() {
    // Probably something like self++ ???
  }

};


int someFunction() {
  number val = 100;
  val.increment();
  return val;
}

---

I've seen it done enough times but have no clue how to actually implement it.

I guess I could always study the string class . . .

First off, you wouldn't be actually incrementing the class. You'd be incrementing some base type that the class contains. Example:

Code:

---

class Number {
    private:
        int num;
    public:
        Number( ) { num = 0; }
        void Increment( ) { num++; }
};

---

Because really, what else would you be incrementing? There has to be something to actually increment.

Quzah.

You know how you can do a

Code:

---

string somestring = "Hello there";
somestring.replace(4, 2, "xx");

---

I want to know how they are able to do that.

Maybe it's not something you can do with a class . . .

the replace function is one that works with strings.

If you wanted to do the same thing with your class, then you would need to write a function that would do that.

Later,

The replace function was used just as an example. I guess I'm not explaining it clear enough.

Are you just wanting to increment one value held inside of the class?
If so, that is simple.
Create a function ( declared public as part of the class ) that will increment the value that you want.

>>I want to know how they are able to do that.

>>Maybe it's not something you can do with a class . . .

You can do anything with a class!

Anyhow, I don't understand your question, so I will leave it at that :)

When you use the ANSI string class you can do a 'string stringname="text"'

Using that string you can do things like "stringname.insert(foo)" and "stringname.erase(foo)". Of course foo isn't valid syntax for those commands.

Using classes I know how to do things like:

Code:

---

class someclass {
public:
  int val;
  int someotherval;

  void somefunction() {}

};

someclass object;
object.val = 10;
object.somefunction();

---

and so on . . .

What I want to know is how they are able to assign a value to "stringname" without needing to do something like "stringname.val = somevalue".

Hope this clarifies my question a bit.

It's called operator overloading. It is a tool that enables you to use more natural syntax for your classes. In essence, it works like this:

Code:

---


class DoubleNum {

private:

int value1;
int value2;

public:

DoubleNum():value1(0), value2(0){}

void operator = (int this_value) {
  value1 = this_value;
  value2 = this_value;
 }

void print() {
  cout << endl << "Value One: " << value1 << endl
  << "Value Two: " << value2 << endl;
 }
};


int main()
 {
  DoubleNum d;
  d.print();
  d = 12;
  d.print();
  system("pause");
  return 0;
 }

---

Thank you!!!! I owe you a beer.