Object Expressions and Anonymous Objects

What is an Object Expression?

In Kotlin, you can create objects without explicitly declaring a class. This is done using object expressions, which allow you to define an object and its behavior directly at the point of use. Object expressions are especially useful when you need to create an object with a slight modification or to provide an implementation for an interface or an abstract class for a single use.

Anonymous Objects

When you use an object expression, the object created is called an anonymous object. This means the object does not have a specific name or type, other than the one it implements or extends. Anonymous objects are often used as quick, one-off implementations, especially for interfaces or abstract classes.

Object expressions are ideal when you need a simple, one-time object that implements an interface or extends a class, without the overhead of creating a separate named class. In the example above, you defined an anonymous object that implements the ClickListener interface. This approach is especially useful for event handling, callbacks, or whenever you need a quick custom implementation for an interface or abstract class. By using object expressions, your code becomes more concise and easier to read, reducing boilerplate and keeping relevant logic close to where it is used.