Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.
References and Dereferences | Pointers
C Basics

References and Dereferences

Pointers are built around two operators:

  • The address-of operator &.
  • The dereference operator *.

Address-of Operator

The address-of operator, represented by &, allows us to directly interact with our computer's RAM. Using & lets you obtain the actual memory address of an object.

c

Main.c

Note

%p is the format specifier used for addresses (pointer).

Addresses are typically expressed in hexadecimal notation.

Think of the & operator as identifying your home's address using your name.

Dereference Operator

Conversely, the * operator gives you the resident's name when given their address. So, how can we employ this operator if we're not directly dealing with addresses? If you have an expression like &x, which returns the address of the x variable, applying the * operator to it (*&x) gives you the value of the variable stored at that address.

Note

Essentially, *&x is the same as x.

c

Main.c

Note

Don't mix up the dereference operator (*x) with the multiplication operator (x*y).

Task

  • Create an integer array of 5 elements and populate it.
  • Retrieve the address of the third element.
  • Increment the address of the third element (i.e., address + 1).
  • Attempt to dereference the address obtained in the previous step.

Everything was clear?

Section 6. Chapter 2
toggle bottom row
course content

Course Content

C Basics

References and Dereferences

Pointers are built around two operators:

  • The address-of operator &.
  • The dereference operator *.

Address-of Operator

The address-of operator, represented by &, allows us to directly interact with our computer's RAM. Using & lets you obtain the actual memory address of an object.

c

Main.c

Note

%p is the format specifier used for addresses (pointer).

Addresses are typically expressed in hexadecimal notation.

Think of the & operator as identifying your home's address using your name.

Dereference Operator

Conversely, the * operator gives you the resident's name when given their address. So, how can we employ this operator if we're not directly dealing with addresses? If you have an expression like &x, which returns the address of the x variable, applying the * operator to it (*&x) gives you the value of the variable stored at that address.

Note

Essentially, *&x is the same as x.

c

Main.c

Note

Don't mix up the dereference operator (*x) with the multiplication operator (x*y).

Task

  • Create an integer array of 5 elements and populate it.
  • Retrieve the address of the third element.
  • Increment the address of the third element (i.e., address + 1).
  • Attempt to dereference the address obtained in the previous step.

Everything was clear?

Section 6. Chapter 2
toggle bottom row
some-alt