What is boilerplate code?

A coworker had never heard of this, and I couldn't provide a real definition. For me, it's always been an instance of 开发者_运维百科'I-know-it-when-I-see-it'.

Bonus question, who originated the term?

"boilerplate code" is any seemingly repetitive code that shows up again and again in order to get some result that seems like it ought to be much simpler.

It's a subjective definition.

The term comes from "boilerplate" in the newspaper industry: wiki

Boilerplate code means a piece of code which can be used over and over again. On the other hand, anyone can say that it's a piece of reusable code.

The term actually came from the steel industries.

For a little bit of history, according to Wikipedia:

In the 1890s, boilerplate was actually cast or stamped in metal ready for the printing press and distributed to newspapers around the United States. 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.

Now according to Wikipedia:

In object-oriented programs, classes are often provided with methods for getting and setting instance variables. The definitions of these methods can frequently be regarded as boilerplate. Although the code will vary from one class to another, it is sufficiently stereotypical in structure that it would be better generated automatically than written by hand. For example, in the following Java class representing a pet, almost all the code is boilerplate except for the declarations of Pet, name and owner:

public class Pet {
    private PetName name;
    private Person owner;

    public Pet(PetName name, Person owner) {
        this.name = name;
        this.owner = owner;
    }

    public PetName getName() {
        return name;
    }

    public void setName(PetName name) {
        this.name = name;
    }

    public Person getOwner() {
        return owner;
    }

    public void setOwner(Person owner) {
        this.owner = owner;
    }
}

On the etymology the term boilerplate: from http://www.takeourword.com/Issue009.html...

Interestingly, the term arose from the newspaper business. Columns and other pieces that were syndicated were sent out to subscribing newspapers in the form of a mat (i.e. a matrix). Once received, boiling lead was poured into this mat to create the plate used to print the piece, hence the name boilerplate. As the article printed on a boilerplate could not be altered, the term came to be used by attorneys to refer to the portions of a contract which did not change through repeated uses in different applications, and finally to language in general which did not change in any document that was used repeatedly for different occasions.

What constitutes boilerplate in programming? As may others have pointed out, it is just a chunk of code that is copied over and over again with little or no changes made to it in the process.

It's code that can be used by many applications/contexts with little or no change.

Boilerplate is derived from the steel industry in the early 1900s.

From Wikipedia:

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 that are considered verbose, i.e. the programmer must write a lot of code to do minimal jobs.

So basically you can consider boilerplate code as a text that is needed by a programming language very often all around the programs you write in that language.

Modern languages are trying to reduce it, but also the older language which has specific type-checkers (for example OCaml has a type-inferrer that allows you to avoid so many declarations that would be boilerplate code in a more verbose language like Java)

Boilerplate is what good programmers avoid: repetition.

Boilerplate in software development can mean different things to different people but generally means the block of code that is used over and over again.

In MEAN stack development, this term refers to code generation through use of template. It's easier than hand coding the entire application from scratch and it gives the code block consistency and fewer bugs as it is clean, tested and proven code and it's open source so it is constantly getting updated or fixed therefore it saves a lot of time as using framework or code generator. For more information about MEAN stack, click here.

Boilerplate definition is becoming more global in many other programming languages nowadays. It comes from OOP and hybrid languages that have become OOP and were before procedual have now the same goal to keep repeating the code you build with a model/template/class/object hence why they adapt this term. You make a template and the only things you do for each instance of a template are the parameters to individualize an object this part is what we call boilerplate. You simply re-use the code you made a template of, just with different parameters.

Synonyms
a blueprint is a boilerplate
a stencil is a boilerplate
a footer is a boilerplate
a design pattern for multiple use is a boilerplate
a signature of a mail is a boilerplate

In practical terms, boilerplate code is the stuff you cut-n-paste all over the place. Often it'll be things like a module header, plus some standard/required declarations (every module must declare a logger, every module must declare variables for its name and revision, etc.) On my current project, we're writing message handlers and they all have the same structure (read a message, validate it, process it) and to eliminate dependencies among the handlers we didn't want to have them all inherit from a base class, so we came up with a boilerplate skeleton. It declared all the routine variables, the standard methods, exception handling framework — all a developer had to do was add the code specific to the message being handled. It would have been quick & easy to use, but then we found out we were getting our message definitions in a spreadsheet (which used a boilerplate format), so we wound up just writing a code generator to emit 90% of the code (including the unit tests).

In a nutshell, boilerplate codes are repetitive codes required to be included in the application with little to no change by the program/framework, and contribute nothing to the logic of the application. When you write pseudo codes you can remove boilerplate codes. The recommendation is to use a proper Editor that generates boilerplate codes.

in HTML, the boilerplate codes in the interface.

<!DOCTYPE html>   
<html>   
   <head>   
      <title></title>   
   </head>   
   <body> </body>   
</html>

in C#, The boilerplate codes of properties.

class Price
{   
  private string _price;   
  public string Price
  {   
     get {return _price;}   
     set {_price= value;}   
  }   
}  

Joshua Bloch has a talk about API design that covers how bad ones make boilerplate code necessary. (Minute 46 for reference to boilerplate, listening to this today)

You can refer to it as "snippets" or more accurately "collection of snippets" . The term I think was coined from the press and printing industry, where they used actual "plates" and then re-used them as chunks again.. In modern-day internet it is a part of an ongoing (annoying IMHO) trend of using fancy terms for simple things in order to look more trendy and sophisticated . see RESPONSIVE = adaptable / fluid.

From whatis.techtarget.com :

In information technology, a boilerplate is a unit of writing that can be reused over and over without change. By extension, the idea is sometimes applied to reusable programming as in "boilerplate code." The term derives from steel manufacturing, where boilerplate is steel rolled into large plates for use in steam boilers. The implication is either that boilerplate writing has been time-tested and strong as "steel," or possibly that it has been rolled out into something strong enough for repeated reuse.

Beyond programming :

A boilerplate can be compared to a certain kind of template, which can be thought of as a fill-in-the-blanks boilerplate. Some typical boilerplates include: mission statements, safety warnings, commonly used installation procedures, copyright statements, and responsibility disclaimers.

In my experience as a programmer, the proper kind of boilerplate code is typically a bunch of code that you start off with that's not large and/or complicated enough to be called a framework.

A typical example would be the HTML5 Boilerplate.

A boilerplate is a unit of writing that can be reused over and over without change. By extension, the idea is sometimes applied to reusable programming, as in “boilerplate code

Repeatable sections of code which just adds an unnecessary layer of typing to get the job done.

Are these necessary?

For the most part, these are structural and decorative markups. It provides consistency on how a code, function, language could look like.

So its kind of redundant as developers because we have seen it multiple times, but does convey some actual meaning to non-developers and compilers.