Indirection

In <a href="/facts/Computer_programming/QmSsFnu0">computer programming</a>, an indirection (also called a reference) is a way of referring to something using a name, reference, or container instead of the value itself. The most common form of indirection is the act of manipulating a value through its <a href="/facts/Memory_address/7EsUmbea">memory address</a>. For example, accessing a <a href="/facts/Variable_(programming)/VoCKtwml">variable</a> through the use of a <a href="/facts/Pointer_(computer_programming)/fPoNzy9b">pointer</a>. A stored pointer that exists to provide a reference to an object by double indirection is called an indirection node. In some older computer architectures, indirect words supported a variety of more-or-less complicated <a href="/facts/Addressing_mode/g78wINgK">addressing modes</a>.
Another important example is the <a href="/facts/Domain_name_system/rfxdWFsj">domain name system</a> which enables names such as en.wikipedia.org to be used in place
of network addresses such as 208.80.154.224. The indirection from human-readable names to network addresses means that the references to a web page become more memorable, and links do not need to change when a web site is relocated to a different server.

Indirection open-in-new

Indirection