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Boilerplate is any text that is or can be reused in new contexts or applications without being changed much from the original. Many computer programmers often use the term boilerplate code. A legal boilerplate is a standard provision in a contract. The term can also be used to describe text that is unnecessary due to its repetitiveness.

[edit] Etymology

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The term dates back to the early 1900s, referring to the thick, tough steel sheets used to build steam boilers. From the 1890s onwards, printing plates of text for widespread reproduction such as advertisements or syndicated columns were cast or stamped in steel (instead of the much softer and less durable lead alloys used otherwise) ready for the printing press and distributed to newspapers around the United States. They came to be known as 'boilerplates'. Until the 1950s, thousands of newspapers received and used this kind of boilerplate from the nation's largest supplier, the Western Newspaper Union.

Some companies also sent out press releases as boilerplate so that they had to be printed as written. The modern equivalent is the press release boilerplate, or "boiler," a paragraph or two that describes the company and its products.

The word has also come into use for pre-created form letters on the Internet for things such as issues to be broached by a politician based on an issue ad, requesting a cable network be added to a system by a cable or satellite operator, or a pre-written complaint about something such as a program, book, or video game opposed by a group which created the letter, along with online petitions. Usually the greeting and the body of the letter have been pre-written, requiring the person requesting the action to only type or sign their name at the end.

[edit] Boilerplate language

The term "boilerplate" has been adopted by lawyers to describe those parts of a contract that are considered "standard language", although it is good practice to always read the boilerplates in any contract.

[edit] Boilerplate code

In computer programming, boilerplate is the term used to describe sections of code that have to be included in many places with little or no alteration. It is more often used when referring to languages which are considered verbose, i.e. the programmer must write a lot of code to do minimal jobs. The need for boilerplate can be reduced through high-level mechanisms such as metaprogramming (which has the computer automatically write the needed boilerplate text) and convention over configuration (which provides good default values, reducing the need to specify program details in every project).

A related term is bookkeeping code, referring to code that is not part of the business logic but is interleaved with it in order to keep data structures updated or handle secondary aspects of the program.

[edit] Preambles

One form of boilerplate consists of declarations which, while not part of the program logic or the language's essential syntax, are added to the start of a source file as a matter of custom. The following Perl example demonstrates boilerplate:

 #!/usr/bin/perl use warnings; use strict; 

The first line is a shebang, which identifies the file as a Perl script that can be executed directly on the command line. The other two are pragmas turning on warnings and strict mode, which are mandated by good Perl programming style.

Preambles often include imports, that is declarations of which libraries are being used. For example the following lines are very frequently included in C programs:

 #include <stdio.h> #include <stdlib.h> 

This tells the compiler to include the files stdio.h and stdlib.h, which contain declarations of the types of commonly used library functions, making them available for use in the rest of the source file.

[edit] See also

• Library (computer science).

[edit] External links

• On the etymology