pointers - How to access a dynamic array in two different functions c++ -

i need access dynamic array in 2 different functions. changes made in 1 need transfer on other.

these functions:

void populate(int size, int *ptr) {     ptr = new int[size];     (int = 0; < size; i++)     {         ptr[i] = rand() % 51;     } }  void display(int size, int *ptr) {     (int i=0; < size; i++)     {         cout << ptr[i] << endl;     } } 

it called in main

int* ptr = null; 

in populate, attempting make pointer pass function point dynamically allocated array. pass pointer value. has no effect on caller side, , results in memory leak. need pass either pointer reference:

void populate(int size, int*& ptr)                             ^ 

or return it

int* populate(int size) {    int* ptr = new int[size];    ....    return ptr; } 

but easiest , safest thing use std::vector<int> both functions instead. example

std::vector<int> populate(size_t size) {     std::vector<int> v(size);     (auto& : v)     {         = rand() % 51;     }     return v; }  void display(const std::vector<int>& v) {   (auto : v)   {     std::cout << ptr[i] << std::endl;   } } 

this way, clear being returned, , caller doesn't have read on whether have manage resources pointed @ raw pointer.

note populate can replaced call std::generate, , display call std::copy.