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Lesson 20 - Equals(), clone() and data classes in Kotlin

Kotlin OOP Equals(), clone() and data classes in Kotlin

In the previous lesson, Enumerated types and constants in Kotlin, we went over the enumerated types and constants in Kotlin. In today's tutorial, we're going to focus on the equals() method and introduce object cloning.

The equals() method

The equals() method is related to comparing objects. We already know that we use it to compare strings. The == operator works for standard data types, such as Int or Double, as we would expect it to. However, when we try to compare 2 objects using ==, we'll get true only if we're comparing 2 references to the same object. If we create a class and 2 different instances of that class, those are still 2 different objects. Their values are the same, but the objects are not the same.


 

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In this tutorial, we'll override the equals() method so it can compare objects via their internal state. Then we'll explain cloning and data classes.

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