Question

Analyze the following code. // Program 1: public class Test { public static void main(String[] args) { Object a1 = new A(); Object a2 = new A(); System.out.println(a1.equals(a2)); } } class A { int x; public boolean equals(Object a) { return this.x == ((A)a).x; } } // Program 2: public class Test { public static void main(String[] args) { Object a1 = new A(); Object a2 = new A(); System.out.println(a1.equals(a2)); } } class A { int x; public boolean equals(A a) { return this.x == a.x; } }

Answer 1

Answer:

Hi there! The question is quizzing on your knowledge of type casting. Please find the explanation below.

Explanation:

The first program declares a Test class containing the main function in which two objects of class A are created and compared. The main function is the entry point of a Java program. After objects a1 and a2 are created, their comparison function “equals” is invoked and the result printed on the screen with the “System.out.println” method. The second program is the same in this respect, except for the implementation of class A. In the first program, class A has the property “x” defined as an int. The method “equals” accepts any object and type casts (converts) the passed object to a type of class A and compares and returns whether the property x of the type-casted object matches the property of the current object a. In the second program, the equals method of class A only accepts an input parameter of class A and returns whether the property x of the type-casted object matches the property of the current object a.