Compare objects for equality
Normally using == between two instances will only return true if they are the exact same objects in the memory. If "only" all the attributes are the same then == will be false.
To be able to compare two objects based on their attributes only we can used the def_equals macro.
class Person def_equals @name, @height property name : String property height : Float64 def initialize(@name, @height) end end prs1 = Person.new(name: "Jane", height: 173.1) prs2 = prs1.dup prs3 = Person.new(name: "Jane", height: 173.1) prs4 = prs1 prs5 = Person.new(name: "Jane", height: 173.2) p! prs1 p! prs2 p! prs3 puts prs1 == prs2 # true puts prs1 == prs3 # true puts prs1 == prs4 # true puts prs1 == prs5 # false