dynamic memory allocation cpp code example

Example 1: dynamic memory allocation

int *p = new int; // request memory
*p = 5; // store value

cout << *p << endl; // Output is 5

delete p; // free up the memory

cout << *p << endl; // Output is 0

Example 2: 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 3: dynamic memory allocation in c++

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

Example 4: dynamic memory management c++

// declare an int pointer
int* pointVar;

// dynamically allocate memory
// using the new keyword 
pointVar = new int;

// assign value to allocated memory
*pointVar = 45;

Example 5: 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;
}