private variables, functions help

Hey all i am having some problems with an assignment of mine. This is the code it reffences to:

Code:

---

class xClass
{
public:
    void func();
    void print() const;
    xClass ();
    xClass (int, double);

private:
    int u;
    double w;
{;

---

The questions are:

Quote:

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1) Write the definition of the member function func so that u is set to 10 and w is set to 15.3.
2) Write the definition of the member function print that prints the contents of u and w.
3) Write the definition of the default constructor of the class xClass so the private member variables are initialized to 0.

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So far this is what i have for the answers-but im not quite sure i am correct.

Code:

---

1)
void xClass::func()
{
    xClass exmpD;
    exmpD.u = 10;
    exmpD.w = 15.3;
}

2)
void xClass::print() const
{
    cout << u << " " << w << end1;
}

3)
public:
set2Zero()
{
    u = 0;   
    w = 0; 
}

---

So, how do my answers look? Am i wayyyy off? :)

David

Decently close.

Remember that you are writing a member function of the class, so everything that is also a member of that class will be available to you. Thus in your func function you can just write u = 10, and w = 15.3. The way you have it now, you are creating an object of the class, assigning variables, and it just so happens that in this fashion your object will be destroyed at the end of the call.

Code:

---

void xClass::func()
{
    u = 10;
    w = 15.3;
}

---

Also a destructor has a special syntax of ~ClassName() in c++. You should put your set to zero calls as the assignment states in this function. Or just call your set2Zero function from the destructor.

Code:

---

xClass::~xClass()
{
  u = 0;
  w = 0;
}

---

Quote:

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Originally Posted by valaris

Also a destructor has a special syntax of ~ClassName() in c++. You should put your set to zero calls as the assignment states in this function. Or just call your set2Zero function from the destructor.

Code:

---

xClass::~xClass()
{
  u = 0;
  w = 0;
}

---

---

Why would you bother to change inert state inside a destructor?

Quote:

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Originally Posted by brewbuck

Why would you bother to change inert state inside a destructor?

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Mostly because I quickly read the post and his assignment requirements and could have sworn it wanted the destructor to do this.

Quote:

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Originally Posted by StealthRT

Code:

---

1)
void xClass::func()
{
    xClass exmpD;
    exmpD.u = 10;
    exmpD.w = 15.3;
}

---

---

I'll add an analogy to this.
Suppose you tell your car to start the engine. This should call Car::StartEngine.
Then in StartEngine, the car creates another car and tries to that that cars engine (which it possibly cannot do, nor should it).
Makes sense? I didn't think so.
The car would want to start its own engine in this case, just as xClass::func would set its own member variables to values and not another instance's.

For 3, you need to write a constructor, not just another method. The syntax looks like writing a function with the name of the class. Also, for constructors, you can use an initializer list to initialize variables. Look that one up.

On a different note, it is convention to start class names with capital letters.

Don't waste your time, he's already received his help at other forums where he posted, like here, here, and here.