equals(), hashCode() & Identity

Override equals() + hashCode() OFF = default (compare by reference) · ON = compare by value OFF · identity

two Point objects edit a coord to make them differ

p1 @0x1A

hashCode()—

p2 @0x2B

hashCode()—

identity checks live

p1 == p2reference equality — same object? false

p1.equals(p2)value equality — same contents? false

hashCode() matchdo the two hashes agree? false

HashSet<Point> add → bucket → equals

set.size() 0

console

▸ With the override OFF, two equal points sneak into the set as duplicates (size 2). Flip it ON so equals + hashCode agree — the duplicate is caught (size 1).