The object equals contract indicates that when two objects are equal, their hash codes must also be the same. It’s a general agreement for all Java objects used in hash-based collections. Its main purpose is to optimize performance when working e.g. with HashMap or HashSet. A) The output is "true" and MyStuff fulfills the Object.equals() contract. B) The output is "false" and MyStuff fulfills the Object.equals() contract. C) The output is "true" and MyStuff does NOT fulfill the Object.equals() contract. D) The output is "false" and MyStuff does NOT fulfill the Object.equals() contract E) Compilation fails Java SE defines a contract that our implementation of the equals() method must fulfill. Most of the criteria are common sense. The equals() method must be: reflexive: an object must equal itself; symmetric: x.equals(y) must return the same result as y.equals(x) transitive: if x.equals(y) and y.equals(z) then also x.equals(z) A) The output is true and MyStuff fulfills the Object.equals() contract. B) The output is false and MyStuff fulfills the Object.equals() contract. C) The output is true and MyStuff does NOT fulfill the Object.equals() contract.
However, the equals() method does not fulfill the Object.equals() contract, which you can read about here. The relevant bit is: It is reflexive: for any non-null reference value x, x.equals(x) should return true. It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
equals() contract. The output is "false" and MyStuff does NOT fulfill the Object. equals() contract. Compilation fails. An exception is thrown at run Indicates whether some other object is "equal to" this one. contract for the hashCode method, which states that equal objects must have equal hash codes. 12 Feb 2020 Learn about the contracts that equals() and hasCode() need to fulfill and The Object class defines both the equals() and hashCode() methods The hashCode() method is another method in Object class. The contract is that if two objects are equal(by using equals() method), they must have the same 22 Aug 2019 What is the contract between equals() and hashcode()? Learn how In this case, the methods are not fulfilling the real purpose of equals() and 15 Jul 2019 Either make the method or the class final. Otherwise getClass() is the only way to go to guarantee that the contract for Object.equals is fulfilled.".
A) The output is true and MyStuff fulfills the Object.equals() contract. B) The output is false and MyStuff fulfills the Object.equals() contract. C) The output is true and MyStuff does NOT fulfill the Object.equals() contract.
7 Dec 2018 Object equals contract states two equal objects must have the same class was implemented and if you fulfilled the object equals contract. 2 Apr 2015 D) The output is "false" and MyStuff does NOT fulfill the Object.equals() contract. E) Compilation fails. Now before I get called on the carpet by equals() contract. The output is "false" and MyStuff does NOT fulfill the Object. equals() contract. Compilation fails. An exception is thrown at run Indicates whether some other object is "equal to" this one. contract for the hashCode method, which states that equal objects must have equal hash codes. 12 Feb 2020 Learn about the contracts that equals() and hasCode() need to fulfill and The Object class defines both the equals() and hashCode() methods The hashCode() method is another method in Object class. The contract is that if two objects are equal(by using equals() method), they must have the same 22 Aug 2019 What is the contract between equals() and hashcode()? Learn how In this case, the methods are not fulfilling the real purpose of equals() and
5 May 2016 The equals method is defined in Object and since all classes inherit from it Any implementation of equals must adhere to a specific contract or
22 Aug 2019 What is the contract between equals() and hashcode()? Learn how In this case, the methods are not fulfilling the real purpose of equals() and 15 Jul 2019 Either make the method or the class final. Otherwise getClass() is the only way to go to guarantee that the contract for Object.equals is fulfilled.". 5 May 2016 The equals method is defined in Object and since all classes inherit from it Any implementation of equals must adhere to a specific contract or The output is "true" and MyStuff fulfills the Object.equals () contract. The output is "false" and MyStuff fulfills the Object.equals () contract. The output is "true" and MyStuff does NOT fulfill the Object.equals () contract. The output is "false" and MyStuff does NOT fulfill the Object.equals () contract. Compilation fails.
However, the equals() method does not fulfill the Object.equals() contract, which you can read about here. The relevant bit is: It is reflexive: for any non-null reference value x, x.equals(x) should return true. It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
A) The output is "true" and MyStuff fulfills the Object.equals() contract. B) The output is "false" and MyStuff fulfills the Object.equals() contract. C) The output is "true" and MyStuff does NOT fulfill the Object.equals() contract. D) The output is "false" and MyStuff does NOT fulfill the Object.equals() contract E) Compilation fails