Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.Learn Pointers Use Cases | Pointers Fundamentals
C++ Pointers and References

bookPointers Use Cases

When you pass a variable to a function, you're essentially passing its value. This means the function receives a copy of the data. Any modifications made inside the function do not affect the original variable.

main.cpp

main.cpp

copy

              
12345678910

            
#include <iostream>

void increment(int num) { num++; }

int main() 
{
    int num = 5;
    increment(num);
    std::cout << "Original value: " << num << std::endl;
}

We can use pointers to enable a function to alter the original variable. This involves passing a memory address as an argument instead of the actual value.

main.cpp

main.cpp

copy

              
123456789101112

            
#include <iostream>

void increment(int* num) { (*num)++; }

int main() 
{
	int num = 5;
    int* p_num = &num;	

    increment(p_num);
    std::cout << "Original value: " << num << std::endl;
}

Note

You can bypass the creation of a pointer to a variable and instead directly use the address-of operator when passing a variable.

Task

Swipe to start coding

Write a function that swaps the values of two integer variables using pointers.

  1. Create a function swap that takes two pointers to integers as parameters.
  2. Inside the function, use a temporary variable to store the value of the first variable.
  3. Assign the value of the second variable to the first variable using pointer dereferencing.
  4. Assign the value from the temporary variable to the second variable using pointer dereferencing.
  5. In main, call swap, passing the addresses of the two variables.

Solution

solution.cpp

solution.cpp

Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 1. ChapterΒ 4
single

single

Ask AI

expand

Ask AI

ChatGPT

Ask anything or try one of the suggested questions to begin our chat

Suggested prompts:

Can you explain how to use the address-of operator when passing a variable?

What is the difference between passing by value and passing by pointer?

Can you give an example of passing a variable by pointer?

close

Awesome!

Completion rate improved to 5.88

bookPointers Use Cases

Swipe to show menu

When you pass a variable to a function, you're essentially passing its value. This means the function receives a copy of the data. Any modifications made inside the function do not affect the original variable.

main.cpp

main.cpp

copy

              
12345678910

            
#include <iostream>

void increment(int num) { num++; }

int main() 
{
    int num = 5;
    increment(num);
    std::cout << "Original value: " << num << std::endl;
}

We can use pointers to enable a function to alter the original variable. This involves passing a memory address as an argument instead of the actual value.

main.cpp

main.cpp

copy

              
123456789101112

            
#include <iostream>

void increment(int* num) { (*num)++; }

int main() 
{
	int num = 5;
    int* p_num = &num;	

    increment(p_num);
    std::cout << "Original value: " << num << std::endl;
}

Note

You can bypass the creation of a pointer to a variable and instead directly use the address-of operator when passing a variable.

Task

Swipe to start coding

Write a function that swaps the values of two integer variables using pointers.

  1. Create a function swap that takes two pointers to integers as parameters.
  2. Inside the function, use a temporary variable to store the value of the first variable.
  3. Assign the value of the second variable to the first variable using pointer dereferencing.
  4. Assign the value from the temporary variable to the second variable using pointer dereferencing.
  5. In main, call swap, passing the addresses of the two variables.

Solution

solution.cpp

solution.cpp

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 1. ChapterΒ 4
single

single

some-alt