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C++ Pointers and References

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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

cpp

main

copy

              
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 start coding

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

Solution

cpp

solution

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SectionΒ 4. ChapterΒ 4
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book
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

cpp

main

copy

              
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 start coding

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

Solution

cpp

solution

Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 4. ChapterΒ 4
Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
We're sorry to hear that something went wrong. What happened?
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