dynamic allocation c++ code example

Example 1: declare dynamic array c++

int main()
{
  int size;

  std::cin >> size;

  int *array = new int[size];

  delete [] array;

  return 0;
}

Example 2: c++ delete dynamically allocated array

int length = 69;
int * numbers = new int[length];
delete[] numbers;

Example 3: what is dynamic memory allocation in c++

In the dynamic memory allocation the memory is allocated during run time.
The space which is allocated dynamically usually placed in a program segment which is known as heap.
In this, the compiler does not need to know the size in advance.
In C++, dynamic memory allocation means performing memory allocation manually by programmer.
It is allocated on the heap and the heap is the region of a computer memory which is managed by the programmer using pointers to access the memory.
The programmers can dynamically allocate storage space while the program is running but they cannot create a new variable name.
  
Example:

Example 4: c++ allocate dynamic with initial values

int length = 50;
int *array = new int[length]();
// returns 50 length array of 0

Example 5: dynamic memory allocation in c++

char* pvalue  = NULL;         // Pointer initialized with null
pvalue  = new char[20];       // Request memory for the variable

Example 6: dynamic memory allocation in c++

#include <iostream>
using namespace std;

int main () {
   double* pvalue  = NULL; // Pointer initialized with null
   pvalue  = new double;   // Request memory for the variable
 
   *pvalue = 29494.99;     // Store value at allocated address
   cout << "Value of pvalue : " << *pvalue << endl;

   delete pvalue;         // free up the memory.

   return 0;
}