Safe removal of the array - delete[]

zsukal (33)
Hello.
I have problem. I write class witch array int.
I must check that array exist, because i must delete it. 

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// if i use it first time - array not exist i have error
void deleteArr(){
 if (arr != NULL)
  delete[] arr;
}

void setArr(){
 deleteArr();
 int* arr = new int[5];
}
Last edited on
zsukal (33)
In constructor i must write:

 
 
arr = NULL;


;-)
closed account (S6k9GNh0)
Um, wut? I'm pretty sure thats not what you do and is a large source of memory leaks...
Galik (2254)
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void deleteArr(){
 if (arr != NULL)
  delete[] arr;
}


the if statement is not necessary. If arr is set to 0 then delete[] will simply ignore it:


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void deleteArr(){
  delete[] arr;
}


That does the same thing.
Galik (2254)
arr = NULL;

I believe in C++ its considered better to use 0 rather than NULL:


arr = 0;

In a constructor, this should be done in the 'initializer list':

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class Test
{
    int* arr;
public:
    Test() : arr(0)
    {
    }
};
closed account (S6k9GNh0)
Its the same exact thing. It doesn't matter.

And I was under the impression that you were for some reason assigning a data address and then assigning NULL. Not sure why I thought that.
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