I am trying to check wether mylist contains a given object or not, where mylist is an ArrayList of type myCustomClass.
I am trying to check wether mylist contains a given object or not, where
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I am trying to check wether mylist contains a given object or not, where mylist is an ArrayList of type myCustomClass.
If you add an instance of
MyCustomClassto the list, and then check if it contains another instance ofMyCustomClass, it will always return false, unless you override theequalsmethod in your custom class. The equals method checks if another object is functionally equal to this object.Make sure to override the
hashCodemethod each time you override the equals method.hashCodeshould return the same value for two equal objects. Also, equals should be written so that it’s symmetric:a.equals(b)if and only ifb.equals(a).Check equals and hashCode in the javadoc of
java.lang.Object.