Learn Working with Pointers

Using the reference operator & and the dereference operator *, we can create and work with pointers.

A pointer is a data type, just like int, char, or double. The pointer is designed to store an address, which you can obtain using the & operator. To declare a pointer, prepend it with the * character.

main.c


              123
            
int* intPointer; // Pointer to an `int` variable
double* doublePointer; // Pointer to a `double` variable
char* charPointer; // Pointer to a `char` variable

In essence, a pointer is a variable that holds the address of another object.

main.c


              123
            
int x = 100; // Variable
int* pX; // Pointer to an `int` variable
pX = &x; // `pX` now points to `x`

Note

Typically, pointers are named by prefixing the letter p to the name of the object they're pointing to.

When you dereference a pointer, you access the value of the variable it points to.

Main.c


              12345678910111213
            
#include <stdio.h>

int main() {
    int x = 22543; // Variable
    
    int* pX = &x; // `pX` is pointer to `x`

    printf("The value of `pX` is %p\n", pX); // Value of pointer `pX`
    
    printf("The value of `x` by pointer `pX` is %d\n", *pX); // Pointer dereference
    
    return 0;
}

Note

*(&variable) == *pVariable

If you attempt to dereference a null pointer, the compiler will raise an error:

Main.c


              1234567
            
#include <stdio.h>

int main() {
    int* pX;
    printf("x = %p", pX);
    return 0;
}

Task

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Determine the size of int and double pointers.

Solution

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Section 6. Chapter 3

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Using the reference operator & and the dereference operator *, we can create and work with pointers.

main.c


              123
            
int* intPointer; // Pointer to an `int` variable
double* doublePointer; // Pointer to a `double` variable
char* charPointer; // Pointer to a `char` variable

In essence, a pointer is a variable that holds the address of another object.

main.c


              123
            
int x = 100; // Variable
int* pX; // Pointer to an `int` variable
pX = &x; // `pX` now points to `x`

Note

Typically, pointers are named by prefixing the letter p to the name of the object they're pointing to.

When you dereference a pointer, you access the value of the variable it points to.

Main.c


              12345678910111213
            
#include <stdio.h>

int main() {
    int x = 22543; // Variable
    
    int* pX = &x; // `pX` is pointer to `x`

    printf("The value of `pX` is %p\n", pX); // Value of pointer `pX`
    
    printf("The value of `x` by pointer `pX` is %d\n", *pX); // Pointer dereference
    
    return 0;
}

Note

*(&variable) == *pVariable

If you attempt to dereference a null pointer, the compiler will raise an error:

Main.c


              1234567
            
#include <stdio.h>

int main() {
    int* pX;
    printf("x = %p", pX);
    return 0;
}

Task

Swipe to start coding

Determine the size of int and double pointers.

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 6. Chapter 3

single