Pointer to Pointer Dynamic Allocation

A pointer to pointer, denoted as double pointer (**).

This is a pointer that holds the memory address of another pointer. In simple words, it is a variable whose value is the address of another pointer. This concept might sound complex at first, but it provides a powerful mechanism for dealing with advanced dynamic memory allocation.

Syntax

main


              12345678910111213
            
#include <iostream>

int main()
{
    int x = 10;
    int *ptr1 = &x;
    int **ptr2 = &ptr1;

    // Accessing values using double pointer
    std::cout << "Location of ptr2: " << ptr2 << std::endl;
    std::cout << "Location of ptr1: " << *ptr2 << std::endl;
    std::cout << "Value of x: " << **ptr2 << std::endl;
}

ptr1: is a pointer to an integer (int*);
ptr2: is a double pointer to an integer (int**).

Dynamic Allocation of a Two-Dimensional Array

If you want to create a two-dimensional array dynamically (at runtime) you have to use a pointer to a pointer for the rows.

And then initialize each row with dynamic array (like in previous chapter)

Task

Swipe to show code editor

Dynamically allocate a two dimensional array.
Dynamically allocate the arrays as elements.
Free all allocated memory.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 4. Chapter 4

Pointer to Pointer Dynamic Allocation

A pointer to pointer, denoted as double pointer (**).

Syntax

main


              12345678910111213
            
#include <iostream>

int main()
{
    int x = 10;
    int *ptr1 = &x;
    int **ptr2 = &ptr1;

    // Accessing values using double pointer
    std::cout << "Location of ptr2: " << ptr2 << std::endl;
    std::cout << "Location of ptr1: " << *ptr2 << std::endl;
    std::cout << "Value of x: " << **ptr2 << std::endl;
}

ptr1: is a pointer to an integer (int*);
ptr2: is a double pointer to an integer (int**).

Dynamic Allocation of a Two-Dimensional Array

If you want to create a two-dimensional array dynamically (at runtime) you have to use a pointer to a pointer for the rows.

And then initialize each row with dynamic array (like in previous chapter)

Task

Swipe to show code editor

Dynamically allocate a two dimensional array.
Dynamically allocate the arrays as elements.
Free all allocated memory.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 4. Chapter 4

Switch to desktop for real-world practiceContinue from where you are using one of the options below