The Any#equals(other: Any?) method is used to compare two objects to see if they are equal.
The other parameter’s type is Any?, this means that an object of any type, as well as null, can be passed as
an argument to this method.
Any class overriding Any#equals(other: Any?) should respect this contract, accept any object as an argument, and return
false when the argument’s type differs from the expected type. The other parameter’s type can be checked using the
is operator or by comparing the javaClass field:
override fun equals(other: Any?): Boolean {
// ...
if (other?.javaClass != this.javaClass) {
return false
}
// ...
}
However, it is an issue to assume that the equals method will only be used to compare objects of the same type. Casting the
other parameter without a prior test will throw a ClassCastException instead of returning false.
class MyClass {
override fun equals(other: Any?): Boolean {
val that = other as MyClass // may throw a ClassCastException
// ...
}
// ...
}
This rule raises an issue when other parameter’s type has not been tested before a cast operation.
