Class method
A class method is a method associated with a class rather than a particular instance and invoked through a class or class-related object.
The Well-Grounded Rubyist, Fourth Edition
A class method is a method callable directly on a Ruby class object, including methods defined on that object or inherited by its class.
- How it is used
- Assigns object creation, class-wide utilities, and collective operations to a class rather than an individual instance.
- How deep it goes
- Explains direct definitions, inherited callable methods, receiver distinctions, subclass lookup through singleton classes, and addition through an inclusion callback.
- Examples
- Uses ticket-price comparison, temperature conversion, car statistics, subclass calls, and a module callback.
- What you can do after
- Build it from scratch by defining a method on a class object and choosing that receiver when an instance is inappropriate.
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Python How-To
A class method is a method associated with a class that receives the class as its first argument and can access class-level state and behavior.
- How it is used
- Uses class methods mainly as factory methods for creating instances from particular data forms.
- How deep it goes
- Defines @classmethod and cls, demonstrates constructor use, and stops short of deeper implementation internals.
- Examples
- Demonstrates Task construction from dictionaries and text, plus unittest checks for both class methods.
- What you can do after
- Build it from scratch by defining factory methods with @classmethod, cls, and constructor calls, then test them with unittest.
React Quickly, Second Edition
A class method is a function defined as part of a class that can access the class or instance context in which it is invoked.
- How it is used
- Simplifies JSX image rendering and organizes URL-building logic inside a class-based React component.
- How deep it goes
- Distinguishes pure utility methods from instance-dependent methods and compares their functional-component conversions.
- Examples
- Uses an image gallery, getImageSource, image URLs, this.props.index, and equivalent class-to-function implementations.
- What you can do after
- Apply class methods to simplify JSX and convert them into pure or local functions when building functional components.
Read how React Quickly, Second Edition explains class method →
Related concepts
- inheritedincludes · inherited is a Ruby class method callback invoked on a class when that class is subclassed, receiving the new subclass as its argument.
- extendproduced by · extend is a Ruby method that adds the instance methods of one or more modules to a particular object's singleton class.
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