malloc() vs new - GeeksforGeeks

Following are the differences between malloc() and operator new.:

Calling Constructors: new calls constructors, while malloc() does not. In fact primitive data types (char, int, float.. etc) can also be initialized with new. For example, below program prints 10.

#include<iostream>

using namespace std;

int main()

{

    // Initialization with new()

    int *n = new int(10);

    cout << *n;

    getchar();

    return 0;

}
Output:
```
10
```
operator vs function: new is an operator, while malloc() is a function.
return type: new returns exact data type, while malloc() returns void *.
Failure Condition: On failure, malloc() returns NULL where as new throws bad_alloc exception.
Memory: In case of new, memory is allocated from free store where as in malloc() memory allocation is done from heap.
Overriding: We are allowed to override new operator where as we can not override the malloc() function legally.
Size: Required size of memory is calculated by compiler for new, where as we have to manually calculate size for malloc().
Buffer Size: malloc() allows to change the size of buffer using realloc() while new doesn’t

new	malloc
calls constructor	doesnot calls constructors
It is an operator	It is a function
Returns exact data type	Returns void *
on failure, Throws	On failure, returns NULL
Memory allocated from free store	Memory allocated from heap
can be overridden	cannot be overridden
size is calculated by compiler	size is calculated manually

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