Learn Pointers Brief Overview | Working with Pointers and Structs

Dereferencing Operator

A pointer is a variable that contains the address of another object.

Dereference operator "*" returns the value stored at the address.

Declaring and initializing a pointer looks like this:

int* pName = NULL;

main.c


              12345678
            
#include <stdio.h>

int main() 
{
    int* pName = NULL;
    printf("%p\n", pName); // `%p` is a specifier for a pointer
    return 0;
}

Referencing Operator &

The & operator returns the address of an object:

main.c


              12345678
            
#include <stdio.h>

int main() 
{
    int variable;
    printf("%p\n", &variable);
    return 0;
}

A variable of pointer type is used to store the address, which is returned by the & operator.

int variable;
int* pVariable;
pVariable = &variable;

To unpack the contents at the specified address, you must use the * operator on a variable of type pointer.

main.c


              12345678910
            
 #include <stdio.h>

int main()
{
    int variable = 1024;
    int* pVariable = &variable;
    printf("Address: %p\n", pVariable); // `%p` specifier for a pointer
    printf("Returned value by address: %d\n", *(pVariable)); // using `*` to pointer
    return 0;
}

Task

Swipe to start coding

You have a product with a specific price, and you need to increase its value by a given percentage.
Your task is to implement a function that updates the product's price using a pointer.

Inside the updatePrice function:

Use the dereference operator (*) to access the current value stored in memory — for example, *price refers to 100.0.
Calculate the percentage of the current price — *price * percentIncrease / 100.0, which for 10% of 100.0 equals 10.0.
Add this percentage to the original value to get the updated price — *price = *price + (percentage part).
The function doesn't return anything — it directly modifies the value through the pointer.

Example

Initial Price	Increase (%)	Updated Price
100.0	10.0	110.0
250.0	5.0	262.5
80.0	25.0	100.0

Solution

Everything was clear?

Thanks for your feedback!

Section 2. Chapter 1

single

Ask AI

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

Suggested prompts:

Can you explain the difference between the * and & operators in more detail?

Can you give an example of how to use pointers in a function?

What are some common mistakes when working with pointers?

Swipe to show menu

Dereferencing Operator

A pointer is a variable that contains the address of another object.

Dereference operator "*" returns the value stored at the address.

Declaring and initializing a pointer looks like this:

int* pName = NULL;

main.c


              12345678
            
#include <stdio.h>

int main() 
{
    int* pName = NULL;
    printf("%p\n", pName); // `%p` is a specifier for a pointer
    return 0;
}

Referencing Operator &

The & operator returns the address of an object:

main.c


              12345678
            
#include <stdio.h>

int main() 
{
    int variable;
    printf("%p\n", &variable);
    return 0;
}

A variable of pointer type is used to store the address, which is returned by the & operator.

int variable;
int* pVariable;
pVariable = &variable;

To unpack the contents at the specified address, you must use the * operator on a variable of type pointer.

main.c


              12345678910
            
 #include <stdio.h>

int main()
{
    int variable = 1024;
    int* pVariable = &variable;
    printf("Address: %p\n", pVariable); // `%p` specifier for a pointer
    printf("Returned value by address: %d\n", *(pVariable)); // using `*` to pointer
    return 0;
}

Task

Swipe to start coding

You have a product with a specific price, and you need to increase its value by a given percentage.
Your task is to implement a function that updates the product's price using a pointer.

Inside the updatePrice function:

Use the dereference operator (*) to access the current value stored in memory — for example, *price refers to 100.0.
Calculate the percentage of the current price — *price * percentIncrease / 100.0, which for 10% of 100.0 equals 10.0.
Add this percentage to the original value to get the updated price — *price = *price + (percentage part).
The function doesn't return anything — it directly modifies the value through the pointer.

Example

Initial Price	Increase (%)	Updated Price
100.0	10.0	110.0
250.0	5.0	262.5
80.0	25.0	100.0

Solution

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 2. Chapter 1

single