Equality
Equality
In Kotlin there are two types of equality:
- Referential equality (two references point to the same object)
- Structural equality (a check for
equals())
Referential equality
Referential equality is checked by the === operation (and its negated counterpart !==). a === b evaluates to true if and only if a and b point to the same object.
Structural equality
Structural equality is checked by the == operation (and its negated counterpart !=). By convention, an expression like a == b is translated to
a?.equals(b) ?: (b === null)
I.e. if a is not null, it calls the equals(Any?) function, otherwise (i.e. a is null) it checks that
