Conclusion

Great job! You saw the basics of properties while learning about classes, and now you’ve seen the more advanced features Kotlin has to offer. But there’s still a long way to go!

• Properties are variables and constants that are part of a named type.
• Default values can assign a value to a property within the class definition.
• Property initializers and the init block are used to ensure that the properties of an object are initialized when the object is created.
• Custom accessors are used to execute custom code when a property is accessed or set.
• The companion object holds properties that are universal to all instances of a particular class.
• Delegated properties are used when you want to observe, limit or lazily create a property. You’ll want to use lazy properties when a property’s initial value is computationally intensive or when you won’t know the initial value of a property until after you’ve initialized the object.
• lateinit can be used to defer setting the value of a property reference until after the instance is created.
• Extension properties allow you to add properties to a class outside the class definition, for example, if you’re using a class from a library.