1. Which two statements are true about comparing two instances of the same class, given that the equals() and hashCode() methods have been properly overridden? If the equals() method returns true, the hashCode() comparison == must return true. If the equals() method returns false, the hashCode() comparison != must return true. If the hashCode() comparison == returns true, the equals() method must return true. If the hashCode() comparison == returns true, the equals() method might return true.





Ask Your Doubts Here

Type in
(Press Ctrl+g to toggle between English and the chosen language)

Comments

  • By: guest on 02 Jun 2017 01.26 am
    (1) is a restatement of the equals() and hashCode() contract. (4) is true because if the hashCode() comparison returns ==, the two objects might or might not be equal. (2) and (3) are incorrect because the hashCode() method is very flexible in its return values, and often two dissimilar objects can return the same hash code value.
Show Similar Question And Answers
QA->Two satellite are moving in the same circular orbit around the earth they must have the same?....
QA->‘I have been touring different parts of the world. During these travels, I have had the good fortune to come into contact with several saints and maharshis. But I have frankly to admit that I have never come across one who is spiritually greater than Swami Sree Narayana Guru of Kerala” Whose words are these?....
QA->If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same?....
QA->When a ray of light falls on a smooth surface and returns to the same medium, it is called?....
QA->The statements “Protoplasm is the physical basis of life” is given by which person?....
MCQ->Which two statements are true about comparing two instances of the same class, given that the equals() and hashCode() methods have been properly overridden? If the equals() method returns true, the hashCode() comparison == must return true. If the equals() method returns false, the hashCode() comparison != must return true. If the hashCode() comparison == returns true, the equals() method must return true. If the hashCode() comparison == returns true, the equals() method might return true.....
MCQ->What two statements are true about properly overridden hashCode() and equals() methods? hashCode() doesn't have to be overridden if equals() is. equals() doesn't have to be overridden if hashCode() is. hashCode() can always return the same value, regardless of the object that invoked it. equals() can be true even if it's comparing different objects.....
MCQ->x = 0; if (x1.hashCode() != x2.hashCode() ) x = x + 1; if (x3.equals(x4) ) x = x + 10; if (!x5.equals(x6) ) x = x + 100; if (x7.hashCode() == x8.hashCode() ) x = x + 1000; System.out.println("x = " + x); and assuming that the equals() and hashCode() methods are properly implemented, if the output is "x = 1111", which of the following statements will always be true?....
MCQ->Which two statements are true about wrapper or String classes? If x and y refer to instances of different wrapper classes, then the fragment x.equals(y) will cause a compiler failure. If x and y refer to instances of different wrapper classes, then x == y can sometimes be true. If x and y are String references and if x.equals(y) is true, then x == y is true. If x, y, and z refer to instances of wrapper classes and x.equals(y) is true, and y.equals(z) is true, then z.equals(x) will always be true. If x and y are String references and x == y is true, then y.equals(x) will be true.....
MCQ->Which of the following are necessary for Run-time Polymorphism? The overridden base method must be virtual, abstract or override. Both the override method and the virtual method must have the same access level modifier. An override declaration can change the accessibility of the virtual method. An abstract inherited property cannot be overridden in a derived class. An abstract method is implicitly a virtual method.....
Terms And Service:We do not guarantee the accuracy of available data ..We Provide Information On Public Data.. Please consult an expert before using this data for commercial or personal use | Powered By:Omega Web Solutions
© 2002-2017 Omega Education PVT LTD...Privacy | Terms And Conditions