Declaration & Initialization

Lesson 2 of 14 in Coddy's C++ Pointers course.

The syntax for pointer declaration consists of a variable type that the pointer will point to, the asterisk (*) symbol to let the compiler know it's a pointer, and a pointer variable name.

// varType *ptrName;
int *ptr;

We can declare any type of pointer, an int pointer, a string pointer, bool, float, or double, we can point to objects, to structures, etc.

int var = 5;
int *ptr = &var;
cout << "Address of var: " << ptr;

Output:
0x7fffffa84984

In this code, the pointer ptr of type int points to var, and in order to initialize its value so it points to something, we use the ampersand (&) operator to get the value of var.

During declaration we use the asterisk (*) symbol to indicate we are creating a pointer to the specified variable type
If we want to get the address of a given variable we use the ampersand (&) symbol
The asterisk (*) symbol is also used for dereferencing. When you use * in conjunction with a pointer, it allows you to access the value stored at the memory address the pointer is pointing to

int var = 10;
int *ptr = &var;
cout << "Value stored on address " 
 << ptr << " is " << *ptr;

Output:
Value stored on address 0x7fff4ec0de14 is 10

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

Perform the following tasks in your code

Declare a pointer of type bool called boolPtr
Declare an integer called num
Input an integer from standard input and store it in num
Declare an integer pointer called intPtr and initialize its value to be the address of num
Print out the value of intPtr using dereferencing

Try it yourself

#include <iostream>

using namespace std;

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

All lessons in C++ Pointers

1Pointer Fundamentals

Introduction to PointersDeclaration & InitializationArithmetic - Assignment Arithmetic - 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