Thread: Please check my C++

Originally Posted by csonx_p

Alright... I have the read/write functions used in Car class, to read/write from file/screen/keyboard. Now, i also added similar functions inside Contract since i'm gonna read a different file (contract), and display differently too. This i suppose suggests that i should overload '>>' / '<<' for these extra reads/writes. If so, could mean this should happen for any extra read/write i add for whatever class...

Q. My thoughts are to give them same names (i.e read(istream& i) )... My concern is whether the compiler will be confused especially if all have same parameter list, but appearing in different classes!!!

Nope, no problem. It will know from the class itself which of the read() functions you mean.

--
Mats

Originally Posted by csonx_p

Elysia's guilty as charged... He's the one who suggested this, and YES is the answer....

Did I? I can't remember suggesting something like that.
Though I am guilty as charged with not keeping consistent naming conventions.
Sometimes I do MyFunction, sometimes I do my_function and sometimes I do MyVar and sometimes I do myVar and sometimes I do my_var.
Oh well.

Originally Posted by csonx_p

My gr8 apologies to you Elysia... wow, quite interesting though... are u guys a spouses? i mean your brains are almost similar...

Jokes aside, I can certainly say that Elysia is not my spouse (to my knowledge, we have never met)...

--
Mats

Because you don't want the original to be changed in this case.
[It would be a programming error and const allows you to catch that mistake at compile time.]

Originally Posted by csonx_p

Maybe i should rephrase my question, what difference would it make if i leave the '&' out, but still use 'const'?

IF you don't pass by reference, the entire string will be duplicated.
If you pass by reference, the object will not be duplicated. More efficient.
There's no need for const if you don't pass by reference because we use it to protect unwanted changes to the original object.

Originally Posted by csonx_p

My question will be explained by code...

Code:

Class A {

public :
      int getX();
 
private :
      int x;
};

A::getX()
{
      return x;
}

Class B {

public :
      int getValues();

private :
      A data;
};

B::getValues()
{
    data.x; // This doesn't work????? pressing the dot after x doesn't even show x, or getX()
   
}

how do i access x in B?

You can't. The design is simply flawed.
If B is stored in A, then you must use a public interface.
In other words, you may "own" a car, but you still can't access its internals. You must use its public interface (it, pedestals and wheel) to drive it.
This is different from a is-a relationship where a cat is an animal and should therefore be able to access the animal's basic properties.

Originally Posted by csonx_p

Maybe i should rephrase my question, what difference would it make if i leave the '&' out, but still use 'const'?

instead of copying just the address (4-8 bytes) you will copy the whole string calling the copy-constructor

And when the function will be ended - the destructor will be called to clear the temp var created...

A lot of overhead involved

data.getX();
Your public interface.

Originally Posted by csonx_p

Could you give an example on how to access x in this case?

Since getX() is public, you should be able to use data.getX() to get it's value. You can't use x since it's a private member of A.

--
Mats