delete vs delete operators in C++
delete operator deallocates memory and calls the destructor for a single object created with
delete  operator deallocates memory and calls destructors for an array of objects created with
delete on a pointer returned by
new  or
delete  on a pointer returned by
new results in undefined behavior.
The difference between delete and delete in C++
delete  when you
newed an array type, and
delete when you didn't. Examples:
typedef int int_array;
int* a = new int;
int* b = new int;
int* c = new int_array;
delete c; // this is a must! even if the new-line didn't use .
Difference between delete() function and delete operator in c++?
delete() function also do the same job in below code
That is not a "delete function". That is a delete expression where the "operand" is a parenthesised expression.
what is difference [between
The difference is the same as in the following expressions:
1 + 2
1 + (2)
In other words, there is no functional difference. The parentheses are redundant.
What's the difference between delete and ::operator delete() in c++
new T and
new T[n] create objects in memory that they acquire.
delete p and
delete  p destroy objects and release the memory where they were stored.
operator new is a memory allocation function, and
operator delete is a memory deallocation function. They do not do anything more than manage memory, and correspond to C's
They have those names in order to avoid introducing more keywords to the language – "operator new" and "operator delete" are just funky ways of spelling "allocate" and "deallocate".
:: is the scope resolution operator and makes sure that these calls are specifically to the functions defined in the global scope.
The new-expressions and delete-expressions are not equivalent to these functions, but use them behind the scenes for memory management.
If you use
operator new for allocating memory you must then also create an object in that memory, and if you release memory with
operator delete you should first destroy the object that occupies the memory.
delete vs delete
From the standard (5.3.5/2) :
In the first alternative (delete
object), the value of the operand of
delete shall be a pointer to a
non-array object or a pointer to a
sub-object (1.8) representing a base
class of such an object (clause 10).
If not, the behavior is undefined.
In the second alternative (delete
array), the value of the operand of
delete shall be the pointer value
which resulted from a previous array
new-expression. If not, the
behavior is undefined.
So no : they are in no way equivalent !
C/C++ delete vs delete
delete: This frees the memory currently allocated by the pointer the delete is performed upon. It only deletes the memory pointed to by the first variable.
delete : This frees the memory allocated for the whole array. An array consists of several variables - delete frees memory only allocated for the first variable, while delete  does the whole thing.
A good way to think of it is considering delete as an instruction while delete  as a loop; where the array is looped through and delete is called individually on each variable in the array. This is NOT how it works in reality (the real workings are a bit more complicated), but is a good way to understand the diff.
The destructor is called on all objects, because in some cases such as in the case of an array of objects that contain pointers, calling the destructor on only the first element doesn't free all memory.
What's the difference between delete arr and deleting elements in a loop
Well, option 1 exhibits undefined behavior, so the difference is one of correct code and incorrect code.
You can only
delete (or, in this case,
delete) what was returned from
new. The individual elements of the array were not returned by new (nor are they pointers). Calling
delete on a pointer which was not returned by
array + n invokes undefined behavior.
An implementation of
new may allocate a bit more memory than was requested for bookkeeping. It gets a pointer,
p, and then says "ok, now let's look at the info
new created for me at
p - sizeof(some_structure). Now I know that I allocated
n bytes of memory because
some_structure.n tells me so, so I'll clean that up now".
When it attempts to do that on the erroneous pointer you gave it it reads nonsense and anything can happen.
On a side note, prefer
std::copy to copy an array, not a loop.
delete vs delete in a for loop
Both versions of
delete each have two tasks: allocation/deallocation and construction/destruction.
newwill allocate memory and call a constructor.
deletewill call a deconstructor and deallocate memory.
new allocates single chunk of memory and then calls a constructor possibly several times.
delete calls a deconstructor possibly several times and then deallocates a single chunk of memory.
delete multiple times means deallocating multiple chunks of memory whereas using
delete will deallocate a single chunk of memory; using
delete multiple times is not equivalent to using
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