You should override the equals() and hashCode() methods from the Object class. The default implementation of
the equals() and hashcode(), which are inherited from the java.lang.Object uses an object instance’s memory
location (e.g. MyObject@6c60f2ea). This can cause problems when two instances of the car objects have the
same colour but the inherited equals() will return false because it uses the memory location, which is different for
the two instances. Also the toString() method can be overridden to provide a proper string representation of your
object. Points to consider:
• If a class overrides equals(), it must override hashCode().
• If 2 objects are equal, then their hashCode values must be equal as well.
• If a field is not used in equals(), then it must not be used in hashCode().
• If it is accessed often, hashCode() is a candidate for caching to enhance performance.
the equals() and hashcode(), which are inherited from the java.lang.Object uses an object instance’s memory
location (e.g. MyObject@6c60f2ea). This can cause problems when two instances of the car objects have the
same colour but the inherited equals() will return false because it uses the memory location, which is different for
the two instances. Also the toString() method can be overridden to provide a proper string representation of your
object. Points to consider:
• If a class overrides equals(), it must override hashCode().
• If 2 objects are equal, then their hashCode values must be equal as well.
• If a field is not used in equals(), then it must not be used in hashCode().
• If it is accessed often, hashCode() is a candidate for caching to enhance performance.
