Browse Definitions:
Definition

recursion

Contributor(s): Lee Savidge

In computer programming, a recursion (noun, pronounced ree-KUHR-zhion) is programming that is recursive (adjective), and recursive has two related meanings:

1) A recursive procedure or routine is one that has the ability to call itself. This usually means that it has the capability to save the condition it was in or the particular process it is serving when it calls itself (otherwise, any variable values that have been developed in executing the code are overlaid by the next iteration or go-through). Typically, this is done by saving values in registers or data area stacks before calling itself or at the beginning of the sequence where it has just been reentered.

2) A recursive expression is a function, algorithm, or sequence of instructions (typically, an IF, THEN, ELSE sequence) that loops back to the beginning of itself until it detects that some condition has been satisfied. Here is a simple example (using a made-up computer source language):

 

CODELINE1   N=0;      
CODELINE2   IF N=<10 THEN DO WRITE LETTER;   
CODELINE3   ELSE GOTO CODELINE6;
CODELINE4   N=N+1;
CODELINE5   GOTO CODELINE2;
CODELINE6   ...some other instruction

Here, the instructions labeled CODELINE2 through CODELINE5 are recursive until the condition of N having the value of 10. "IF N=<10" means "If N has a value less than 10." "N=N+1" means "Add 1 to the current value of N."

In mathematics, recursion has similar but more complicated meanings than it does when used in programming.

This was last updated in August 2005

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

SearchSecurity

  • Web application firewall (WAF)

    A Web application firewall (WAF) is a firewall that monitors, filters or blocks traffic to and from a Web application. WAFs are ...

  • MD5

    The MD5 hashing algorithm is a one-way cryptographic function that accepts a message of any length as input and returns as output...

  • identity theft

    Identity theft, also known as identity fraud, is a crime in which an imposter obtains key pieces of personally identifiable ...

SearchHealthIT

SearchDisasterRecovery

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

  • mass notification system (MNS)

    A mass notification system is a platform that sends one-way messages to inform employees and the public of an emergency.

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

SearchStorage

  • secondary storage

    Secondary storage is used to protect inactive data written from a primary storage array to a nonvolatile tier of disk, flash or ...

  • VRAM (video ram)

    VRAM (video RAM) is a reference to any type of random access memory (RAM) used to store image data for a computer display.

  • ZFS

    ZFS is a local file system and logical volume manager created by Sun Microsystems to control the placement, storage and retrieval...

SearchSolidStateStorage

  • SSD RAID (solid-state drive RAID)

    SSD RAID (solid-state drive RAID) is a methodology commonly used to protect data by distributing redundant data blocks across ...

  • Tier 0

    Tier 0 (tier zero) is a level of data storage that is faster, and perhaps more expensive, than any other level in the storage ...

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close