What is the difference between double and triple equals in Kotlin, and what is the purpose of the triple equals?

== compares the contents of objects (structural equality) by calling the equals() method. === compares references to objects (referential equality), checking if they point to the same instance in memory.

The triple equals (===) was introduced for explicit reference comparison, which is useful for optimization (e.g., avoiding unnecessary copying or calculations if objects are identical) and in cases where it is necessary to know exactly whether two variables refer to the same instance. In Java, this corresponds to the == operator for objects. In Kotlin, == is overloaded for content comparison, so a separate operator is needed for referential equality.