int array new int n what is this function actually doing

Question

I am confused about how to create a dynamic defined array    int  array   new int n     I have no idea what this is doing   I can tell it s creating a pointer named array that s pointing to a new object array int   Would someone care to explain

User · Accepted Answer

new allocates an amount of memory needed to store the object array that you request  In this case n numbers of int   The pointer will then store the address to this block of memory   But be careful  this allocated block of memory will not be freed until you tell it so by writing  delete    array

User · Answer

It allocates that much space according to the value of n and pointer will point to the array i e the 1st element of array  int  array   new int n

User · Answer

The statement basically does the following    Creates a integer array of  n  elements Allocates the memory in HEAP memory of the process as you are using new operator to create the pointer Returns a valid address  if the memory allocation for the required size if available at the  point of execution of this statement

User · Answer

It allocates space on the heap equal to an integer array of size N  and returns a pointer to it  which is assigned to int  type pointer called  array

User · Answer

int  array   new int n     It declares a pointer to a dynamic array of type int and size n    A little more detailed answer  new allocates memory of size equal to sizeof int    n bytes  and return the memory which is stored by the variable array  Also  since the memory is dynamically allocated using new  you ve to deallocate it manually by writing  when you don t need anymore  of course    delete   array    Otherwise  your program will leak memory of at least sizeof int    n bytes  possibly more  depending on the allocation strategy used by the implementation

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In C C    pointers and arrays are  almost  equivalent  int  a  a 0   will return  a  and a 1   will return   a   1   But array can t change the pointer it points to while pointer can   new int n  will allocate some spaces for the  array

User · Answer

The new operator is allocating space for a block of n integers and assigning the memory address of that block to the int  variable array   The general form of new as it applies to one-dimensional arrays appears as follows   array var   new Type desired size

User · Answer

As of C  11  the memory-safe way to do this  still using a similar construction  is with std  unique ptr   std  unique ptr lt int   gt  array new int n      This creates a smart pointer to a memory block large enough for n integers that automatically deletes itself when it goes out of scope  This automatic clean-up is important because it avoids the scenario where your code quits early and never reaches your delete    array  statement   Another  probably preferred  option would be to use std  vector if you need an array capable of dynamic resizing  This is good when you need an unknown amount of space  but it has some disadvantages  non-constant time to add delete an element   You could create an array and add elements to it with something like   std  vector lt int gt  array  array push back 1       adds 1 to end of array array push back 2       adds 2 to end of array    array now contains elements  1  2

[c++] int *array = new int[n]; what is this function actually doing?

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