Select the correct answerConsider the following Java code:public class Student { private String name; private int age; public Student(String name, int age) { this.name = name; this.age = age; } // Override the equals() method @Override public boolean equals(Object obj) { // TODO: Implement the equals() method } public static void main(String[] args) { Student student1 = new Student("Alice", 20); Student student2 = new Student("Bob", 22); Student student3 = new Student("Alice", 20); System.out.println(student1.equals(student2)); System.out.println(student1.equals(student3)); }}What should be implemented inside the equals() method to correctly compare two Student objects based on their name and age?A. return this.name.equals(obj.name) && this.age == obj.age;B. return this.name.equals(((Student) obj).name) && this.age == ((Student) obj).age;C. return super.equals(obj);D. return this == obj;OptionsCA and BOnly AD
Question
Select the correct answerConsider the following Java code:public class Student { private String name; private int age; public Student(String name, int age) { this.name = name; this.age = age; } // Override the equals() method @Override public boolean equals(Object obj) { // TODO: Implement the equals() method } public static void main(String[] args) { Student student1 = new Student("Alice", 20); Student student2 = new Student("Bob", 22); Student student3 = new Student("Alice", 20); System.out.println(student1.equals(student2)); System.out.println(student1.equals(student3)); }}What should be implemented inside the equals() method to correctly compare two Student objects based on their name and age?A. return this.name.equals(obj.name) && this.age == obj.age;B. return this.name.equals(((Student) obj).name) && this.age == ((Student) obj).age;C. return super.equals(obj);D. return this == obj;OptionsCA and BOnly AD
Solution
The correct answer is B.
Here's why:
In Java, to compare two objects for equality, we override the equals() method. The equals() method takes an Object as a parameter, so we need to cast it to a Student before we can access its fields.
Option A is incorrect because it tries to directly access the fields of the Object parameter without casting it to a Student first. This will result in a compile error.
Option B is correct. It first casts the Object parameter to a Student, then it compares the name and age fields of the current object (this) with those of the parameter object.
Option C is incorrect because it calls the equals() method of the superclass (Object), which checks for reference equality, not field equality.
Option D is incorrect because it checks for reference equality, not field equality. This would only return true if the two references point to the exact same object, not two equal objects.
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