Don't repeat yourself principle

As explained in 100 C++ Mistakes and How to Avoid Them

The DRY principle is the software design principle of avoiding repeated knowledge or behavior across multiple implementations.

How 100 C++ Mistakes and How to Avoid Them covers it

How deep it goes

Explains minimal function bases and demonstrates consolidation, while stopping short of treating every duplication as requiring refactoring.

Examples

Uses a Cylinder with repeated area and volume calculations, then centralizes initialization and derives volume from base area.

What it assumes

Assumes familiarity with constructors and functions while developing the idea of a minimal basis for shared behavior.

What you can do after

Apply it via identifying duplicated behavior and selecting a minimal set of shared operations from which other functions can be implemented.

How it connects

Connects DRY with constructors, methods, standalone functions, class invariants, and code divergence.

liveBookmanning.com

Read 100 C++ Mistakes and How to Avoid Them on liveBook Get the book at manning.com

Also explained in

• 

  liveBookmanning.com
  A Pythonic Adventure: From Python basics to a working web appThe DRY principle is the software-development practice of avoiding duplicated knowledge or implementation by defining it once and reusing it.
• 

  liveBookmanning.com
  Object-Oriented Software Design in C++The Don't Repeat Yourself Principle states that every piece of knowledge or behavior should have a single authoritative representation in a system.
• 

  liveBookmanning.com
  Python Workout: 50 ten-minute exercisesThe software-development principle of avoiding duplicated knowledge or logic by defining it once and reusing it.
• 

  liveBookmanning.com
  Effective Platform EngineeringThe DRY principle is the practice of avoiding duplicated knowledge or logic by maintaining a single authoritative representation.
• 

  liveBookmanning.com
  Software Design for Python ProgrammersThe Don't Repeat Yourself Principle states that each piece of knowledge or behavior should have a single authoritative representation in code.
• 

  liveBookmanning.com
  The Well-Grounded Python Developer: How the pros use Python and FlaskThe DRY principle is the software design principle of avoiding duplicated knowledge or logic in a codebase.
• 

  liveBookmanning.com
  Pandas Workout: 200 exercises to make you a stronger data analystDon't repeat yourself is a software design principle that avoids duplicating logic or equivalent code.
• 

  liveBookmanning.com
  Python How-ToDRY is the software design principle that each piece of knowledge or behavior should have a single authoritative representation.
• 

  liveBookmanning.com
  Python Workout, Second EditionThe DRY principle is a software-development principle that avoids duplicating knowledge or logic by expressing it once and reusing it.

Compare how 10 books explain don't repeat yourself principle →

Related concepts

• code duplicationaddressed by · Code duplication is the presence of equivalent or substantially similar source code or implementation logic in multiple locations within a software system.
• inheritanceused by · Inheritance is a mechanism by which a child type or element receives properties, values, or behavior from a parent, subject to system rules and possible overrides.
• decouplingaddresses · Decoupling is the design practice of reducing direct dependencies between software components so they can change, operate, or evolve more independently.
• moduleaddressed by · A module is a distinct, bounded software unit that groups related code or functionality and provides an organizational or interaction boundary within a larger system.
• functionuses · A function is a callable program unit that performs an operation, may accept inputs, and can produce a result or side effect.

This explainer was generated by Manning's knowledge graph from the text of 100 C++ Mistakes and How to Avoid Them. The section links point to the parts of the book it draws on.