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Hi, Is there any memory leak in the below code... if there are how can resoleve it.thaks..
class test<br />
{<br />
int a;<br />
public:<br />
test(int i):a(i){}<br />
void diplay(test* tst)<br />
{<br />
int i = tst->a+30;<br />
cout<<i<<endl;<br />
}<br />
~test(){}<br />
};<br />
<br />
int main()<br />
{<br />
<br />
<br />
test* test1;<br />
test1->(new test(20));
<br />
return 0;<br />
}<br />
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I've never seen something written like test1->(new test(20)); //debugger telling me here is memory leak. before... what do you expect this line to do???
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sorry..Small typo error..it suppose to be test1->display(new test(30)).It will create pointer to that object while passing as a argument. It may be reducing lines of codes. But my question is is it good practice?
modified on Monday, September 29, 2008 3:39 AM
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well in that case you definitely do have a memory leak, as you are allocating memory with new, but you never called delete on it, and have no way to, because it was never assigned to a variable, but instead simply passed directly into a function.
What you should do is allocate memory to a variable using new first, and then pass that variable to the function, like so;
test * theVar = NULL;
theVar = new test(30);
test1->display(theVar);
Then when you are done with theVar call delete on it and assign NULL to it;
delete theVar;
theVar = NULL;
And then you have no memory leak.
Another thing to keep in mind is to check whether or not theVar is NULL before you use it, so back in my original code snippet you would change it to something like this;
test * theVar = NULL;
theVar = new test(30);
if(theVar != NULL)
{
test1->display(theVar);
}
else
{
}
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it is a litle crappy. 
better:
test1 = new test(20);
//at end
delete test1;
Greetings from Germany
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SRKSHOME wrote: test1->(new test(20));
That is because you are doing memory allocation with new, and you have no way of deleting the pointer to that memory location, since you don't have a variable to delete. Try using a pointer variable and then you can free the memory it points to
Somethings seem HARD to do, until we know how to do them.
 _AnShUmAn_
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There are two bugs in this program:
1. test1->(new test(20)); // This is incorrect. Perhaps you mean test1->display(new test(20));
2. You are using test1 without allocating memory for it.
You can try something like this:
test* test1 = new test;
test* test2 = new test;
test1->display(test2);
delete test1;
delete test2;
Or
test test1;<br />
test test2;<br />
test1.display(&test2);
-Saurabh
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Hi All
I am new in vc++.I have a problem to get length of array.Plz help me
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Thanks for reply but it's not working
i have a CString store[100];,CString File; and int cou=0;. And i use store[cou]=File. And i want to get Size of store[cou].Plz help me
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CArray or user defined array??
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You/xml>
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do you want the size of the array in bytes, or the number of elements in the array?
if you want the size in bytes, use the sizeof() like so;
int size_in_bytes;
int theArray[20];
size_in_bytes = sizeof(theArray);
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Hi,
Dont use user defined array in this case. You better use CStringArray.
Then you no need to calculate the size of the array. This class is having a member function int GetSize() to get the size of the array.
The price of anything is the amount of life you exchange for it.
Thanks and Regards.
SANTHOSH V
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please read at first the docs about the used obejcts carefully. Often there are tiny little helper as .length or .GetLength to solve such problems. (And use the search box in top of this site a lot) 
Greetings from Germany
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What kind of array are you using? Could you please post array declaration?
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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The size of such array is
int iSize = sizeof(store);
The number of elements of such array is
int iCount = sizeof(store)/sizeof(store[0]);
or, more concisely, 100.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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Thanks for reply but it's not working.
CString store[100];
CString File;
and int cou=0;
store[cou]=File.
File name added at the run time.Plz help me
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What does it mean 'it's not working?' in such context?
What are you trying to do?
What happens instead?
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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store[cou]=File;
int iSize=sizeof(store);
AfxMessageBox(iSize);
Then i am geting Debug Assertion Fail Line number:163.
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On what line does the code assert?
BTW your array is fixed-sized to 100 elements, regardless if you assign or not any of them.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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Thank Now it is working.Your code is good.I make a mistake.SO thanks again.Ome more question how can i use dynamic array.Plz help me
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