Questions and Answers
What is an implicit return?
What is a class?
Classes are the basic template from which object instances are created.
When should you use a class?
When you have several methods that could be grouped together to do the smallest possible thing or when you need to construct similar objects.
How do you create a class in your script file?
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What is an instance of a class?
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What is the difference between the CamelCase and snake_case styles of naming?
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How do you instantiate a class?
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How do you set the state of your new instance?
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What should be done in the #initialize method?
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What is a class method?
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How is a class method different from an instance method?
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What is an instance variable?
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What's the difference between an instance variable and a 'regular' variable?
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What are 'getter' and 'setter' methods used for?
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What is the difference between a 'getter' and a 'setter' method?
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Can a class call its own class methods?
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What is scope?
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Study Notes
Classes and Objects
- A class is a template from which object instances are created, consisting of variables representing internal state and methods providing behaviors that operate on that state.
- Classes are used to group methods that do the smallest possible thing or to construct similar objects.
- To create a class, start with the keyword "Class", give the class a name (capitalized and in CamelCase if multiple words), and close with the keyword "end".
Instantiation and State
- An instance of a class is an object created from the class template, carrying its own state and having the same behavior as the class.
- To instantiate a class, set a variable equal to ClassName.new() and pass in any necessary parameters.
- The state of an instance is set by passing in variables required to instantiate it.
Methods
- Instance methods are called on an instance of a class, whereas class methods are called on the class itself.
- Class methods are declared using the "self" keyword, whereas instance methods are declared without it.
- Instance methods are used to perform actions on an instance, while class methods are used to perform actions on the class as a whole.
Variables
- Instance variables are variables that are part of an instance, whereas regular variables are local to a method or block.
- Instance variables are denoted by the "@" symbol, whereas regular variables are not.
- Getter and setter methods are used to access and modify instance variables, respectively.
Inheritance and Scope
- Inheritance allows a class to inherit behavior from another class, promoting code reuse.
- A subclass can extend a superclass using the "<" symbol, inheriting all its methods and variables.
- The "#super" method is used to call a method from a superclass.
- Scope refers to the region of the code where a variable or method is accessible.
- A new scope is defined when a class, module, or method is defined.
Access Control
- Private methods can only be accessed within the class itself, whereas protected methods can be accessed within the class and its subclasses.
- Encapsulation refers to the concept of hiding internal implementation details of an object from the outside world.
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Description
Test your knowledge about classes and methods in Ruby programming. This quiz covers key concepts such as implicit returns and how they function within the language. Enhance your understanding of Ruby's quirks and best practices.