Arithmetic - Assignment

Lesson 3 of 14 in Coddy's C++ Pointers course.

Pointers, like other variables and data types, can have arithmetical/mathematical operations performed on them.

Assigning Values

At a given moment a pointer can point to only one address. But, throughout the program that can be changed and the pointer can be modified to point to something else.
Note: Multiple pointers can point to the same location.

int var = 5;
int *ptr = &var;
int *newPtr = ptr;
cout << "Pointer address: " << ptr << endl;
cout << "2nd pointer address: " << newPtr;

Output:
Pointer address: 0x7fffca8285cc
2nd pointer address: 0x7fffca8285cc

The value of the pointer ptr got assigned to newPtr and now both pointers are pointing to the same variable var, or to the memory address that holds the value 5

int x = 10;
int *ptr = &x;
int *newPtr = ptr;
cout << "x = " << x << endl;
cout << "ptr = " << ptr << endl;
cout << "*ptr = " << *ptr << endl;
*newPtr = 25;
cout << "x = " << x << endl;
cout << "newPtr = " << newPtr << endl;
cout << "*newPtr = "<< *newPtr;

Output:
x = 10
ptr = 0x7ffe28364c9c
*ptr = 10
x = 25
newPtr = 0x7ffe28364c9c
*newPtr = 25

As you can see, we have the integer variable x which equals to 10 we declare the pointers ptr and newPtr to point to the same variable x, we can notice if we look at the memory addresses. Now, we changed the value of *newPtr to 25 and that automatically switched the value of x since newPtr is pointing to it.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

Challenge

Easy

On standard input, you will be given 2 numbers. Input them in variables of your choice, the important part is to create an integer pointer called *ptr and initialize it to point to the first number. Then, assign the value of the second number to the pointer by dereferencing it, and print out its value to standard output

Try it yourself

#include <iostream>

using namespace std;

int main()
{
    
    // Enter your code
    
    return 0;
}

All lessons in C++ Pointers

1Pointer Fundamentals

Introduction to Pointers Declaration & InitializationArithmetic - AssignmentArithmetic - Operations Const Pointers Pointers & Arrays

2Pointers & References

Pointers as Parameters References - &References as Parameters Pointers vs References

3Dynamic Memory Allocation

New & Delete Operators Memory Leaks Dynamic Array Dynamic Array - Insertion