.. highlight:: c++
  :linenothreshold: 5

.. _ptr-type:

************
Pointer Type
************

Basics
======
+ A derived type to store the memory address of an lvalue
+ \* symbol after type to make a derived type ``BaseType *ptr;``
+ \* operator to dereference a pointer variable ``*ptr``
+ & operator to reference an lvalue ``ptr = &lvalue;``

.. _ptr-example:

Example
=======

::

  int value = 10;
  int *ptr1;
  ptr1 = &value;  // reference the value, now you can use *ptr1 as an alias of value
  (*ptr1)++;  // value increased by 1 and become 11

  cout << "The value is " << (*ptr1) << endl;  // dereference

  // type cast to (void *) type to be displayed correctly
  cout << "The memory address is " << static_cast<void *>(ptr1) << endl;

+ Pitfalls

  * confusing pointer syntaxes with reference syntaxes

Pointer Type Based Data Structures
==================================
+ Linked-list
+ Tree
+ Graph
+ Hash Table (chained)

Related Topics
==============
+ :ref:`Pointer syntaxes in array<ptr-array>`
+ :doc:`Reference type vs pointer type</cpp/ref/ref-vs-ptr>`