operator == method - Object class - dart:core library (original) (raw)

bool operator ==(

1. Object other )

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

• Total: It must return a boolean for all arguments. It should never throw.
• Reflexive: For all objects o, o == o must be true.
• Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.
• Transitive: For all objects o1, o2, and o3, if o1 == o2 ando2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Implementation

external bool operator ==(Object other);