RE: **Pointers -- RPG400-L

I think that depends on what you mean by "oblivious." As Paul said, a
pointer simply points to a hunk of memory, it has no knowledge of what's at
that memory location, nor does it care. However, good coding practice, IMHO,
would demand that you not be oblivious to what's at that location. For
example I wouldn't do the following:

------BAD------
TheString       string;
TheInt  int;
TheFloat        float;
ThePointer      pointer;

TheString = "asdsad";
ThePointer = addressof(TheString);
DoSomething(ThePointer);

TheInt = 7;
ThePointer = addressof(TheInt);
DoSomethingDifferent(ThePointer);

TheFloat = 899.332;
ThePointer = addressof(TheFloat);
DoSomethingElse(ThePointer);
------END BAD------

But I would rather see the following:

------GOOD------
TheString               string;
TheStringPointer        pointer;
TheInt          int;
TheIntPointer   pointer;
TheFloat                float;
TheFloatPointer pointer;

TheString = "asdsad";
TheStringPointer = addressof(TheString);
DoSomething(TheStringPointer);

TheInt = 7;
TheIntPointer = addressof(TheInt);
DoSomethingDifferent(TheIntPointer);

TheFloat = 899.332;
TheFloatPointer = addressof(TheFloat);
DoSomethingElse(TheFloatPointer);
------END GOOD------

In the second example the deceloper "knows" what the pointer points to
because he's declared a pointer for a specific purpose and uses it for such.

Just my 2 cents worth.

-Walden

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Walden H Leverich III
President
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Quiquid latine dictum sit altum viditur.
(Whatever is said in Latin seems profound.)



-----Original Message-----
From: Sunil [mailto:sunil_ramakumar@USSWI.com]
Sent: Thursday, May 30, 2002 10:48
To: rpg400-l@midrange.com
Subject: Re: **Pointers


Hai,

In that case when we code can we be oblivious of wheather  a pointer points
to a string or a char or a int.

Sunil



----- Original Message -----
From: "Nicolay, Paul" <paul_nicolay@merck.com>
To: <rpg400-l@midrange.com>
Sent: Thursday, May 30, 2002 8:01 PM
Subject: RE: **Pointers


Hi,

I'll try to be short... a pointer by itself is nothing more than a datatype,
and actually holds the address of a memory location.  What is stored at that
memory location is unknown by the pointer itself.

In C however, when you write *char... it means a pointer to a character
array (in other words a string).  Since C doesn't have the concept of a
string like in RPG, they usually null terminate it, meaning that x number of
bytes further than the memory address a hex null is stored to indicate the
end of the string.

Kind regards,
Paul

-----Original Message-----
From: Sunil [mailto:sunil_ramakumar@USSWI.com]
Sent: 30 May, 2002 16:34
To: rpg400-l@midrange.com
Subject: **Pointers


Hai,

I am a bit new to pointers and the related stuff in RPG. I am confused when
some authors say *char, string* etc. As far as my understanding goes you
cant define a datatype for a pointer ( infact pointer itself is a datatype,
right!!). Am I right? If I am what does *char mean? Does it simply refer to
the data that we know must is stored in the memory space pointed by the
pointer?

Regards

Sunil


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