What is the correct way to dynamically allocate memory.

Question

int *arr = new int(5);
or
int *arr = new int[5];
i am confused...

Answer 1

Both do it:
int *arr = new int(5); Single int with a value of 5;

int *arr = new int[5]; An array with room for 5 integers.

Answer 2

Thanks for sharing Sp Maurya ...

I belive still [] is correct option.... C++ actually not checking size for array i.e. pointer arithmetic while iteration... This is what I feel and () is typo....

This is what I believe and not sure so waiting for others to respond....

My understanding in below code as code comment :

https://code.sololearn.com/c4f5QhY68Vx6/?ref=app

Answer 3

@Sp Maurya
@Ketan Lalcheta
goto:-
https://www.bogotobogo.com/cplusplus/memoryallocation.php

and scroll down to:- " Initializing Dynamically Allocated Objects" (it's about half-way down the page).

Answer 4

Could you please refer that link which suggests int(5) as 5 object? Wana go through it once for details it refers to

Answer 5

Ketan Lalcheta https://www.guru99.com/cpp-dynamic-array.html#:~:text=It's%20easy%20to%20initialize%20a,be%20added%20to%20the%20array.

Answer 6

Ketan Lalcheta yes you are absolutely right... [] this is the correct way but as you also see in your implementation... the same thing was confusing me... lets just consider it as a loop hole in c++ compiler for now... and wait for others to respond...

Answer 7

Oh great rodwynnejones ... It means () is same as int constructor.... New int (5) means it points to some int value whose value is 5.....

So, it solves my doubt that it is not array allocation but only a single element of array...

Answer 8

rodwynnejones but on some sites i found that
int *arr = new int(5);
as an array with room for 5...
that's why i am confused...
and it works as well...
but ya you are also right and i actually know that already...