CODEWITHSUNDEEP
c++
asdfkjasdfjk
asdfkjasdfjk

Reputation: 3894

How to delete 1D array

I create an array like as below

int size = 5;
double my_arr[m_size];

for (int i = 0; i < size; i++)
{
    my_arr[i] = (rand()%10+1) +  ((double) rand() / (RAND_MAX));;
}

after doing some calculation on array I want to delete the array. So I do this 

for (int i = 0; i < size; i++)
    {
       delete my_arr[i]; 
    }

and I get this error 

error: type ‘double’ argument given to ‘delete’, expected pointer

I searched internet and all solutions are related to pointer array. But I am not using any pointer. So how can I delete this array?

Upvotes: 0

Views: 964

Answers (2)

Lor&#232;loi
Lor&#232;loi

Reputation: 168

First of all, I think you should consider using a memory leak detector in your programms, so you can know by yourself if your code is leaking and if you have to do something about it. In your code you would have seen that there is no need to delete anything. :)

As far as I know, you should worry about memory in only two cases:

  • You have allocated a C-style array with malloc or calloc. In this case, you need to use the function free to deallocate the array. But generally in C++, you don't want this. You prefer using a container like std::array or std::vector instead.
  • You have created a new instance of an class with new and you have got a pointer to this instance. In this case, you have to use delete on the pointer when you don't need this instance anymore. But generally in C++11 (or further), you don't want this. If you really have to use a pointer, you prefer creating a smart pointer like std::unique_ptr or std::shared_ptr which will handle the memory for you.

When you define a variable without using new, malloc or calloc, (for example int a = 1 ;), it will be automatically deleted when it goes out of scope. So you don't need to worry.

Here is a simple example of a variable going out of scope:

int a = 1 ;
{
    int b = 1 ;

    // b is implictly deleted here, just before the bracket.
}
a++; // It works, because a exists in this scope
b++; // It doesn't work, because b is out of scope.

// a is implicitly deleted here, assuming we are at the end of a function

Upvotes: 0

Irminsul
Irminsul

Reputation: 181

The array will be automatically deleted when leaving the scope in which the variable has been declared. If you really need to free memory fast you can try put your code between embraces:

{ //create new scope
    int size = 5;
    double my_arr[m_size];

    for (int i = 0; i < size; i++)
    {
        my_arr[i] = (rand()%10+1) +  ((double) rand() / (RAND_MAX));;
    }

    //some stuff

} //all non-pointer objects (or arrays) will be deleted

Or you can use pointers :

double *pMyarr =  new double[m_size] ;

Upvotes: 3

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