Hello again! I am having trouble understanding the issue with my code again. The first if statement compares whether or not the two objects are equal. The second if statement compares whether an object has null. The third if statement compares the two objects to see if they have identical elements.

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package en.codegym.task.pro.task10.task1010; import java.util.Objects; /* Two iPhones */ public class Iphone { private String model; private String color; private int price; public Iphone(String model, String color, int price) { this.model = model; this.color = color; this.price = price; } public boolean equals(Iphone one){ if(this==one) return true; if(this==null) return false; if(this.getClass()== one.getClass()){ Iphone other = (Iphone) one; return model.equals(other.model) && color.equals(other.color) && price==other.price; }else return false; } public static void main(String[] args) { Iphone iphone1 = new Iphone("X", "White", 999); Iphone iphone2 = new Iphone("X", "White", 999); System.out.println(iphone1.equals(iphone2)); } }

The main creates two iPhones with identical properties.
They are compared and the result is displayed on the console. Figure out why the result is currently negative and make it so the result is positive. To do this, you need to override the equals(IPhone) method and account for all the phone properties.
The values of fields must be the same if two objects are equal. The main method is not checked.

Requirements:

The IPhone class must override the public boolean equals(Object) method.
The equals method must return true for two equal IPhone objects and false for different ones.
The equals method must return false if null is passed to it.

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Guadalupe Gagnon

Level 37 , Tampa, United States

19 July 2023, 20:13

A big issue that you have is that you should be over riding the equals method, but instead you over loaded it. The equals method is:

public boolean equals(Object obj) {
    // logic to return true if equals
    // otherwise false
}

line 23 is pointless. If it were true then a NullPointerException would have been thrown when calling the equals() method. Maybe you meant this?

if(one==null)

Gummy C

Level 11 , United States of America, United States

19 July 2023, 22:06

How am I overloading the equals method, I don't really understand. Overloading the equals method would mean that I have created another equals method with different params. Right? But, if I was to override the method wouldn't the class need to inherit something? Can you please explain?

Guadalupe Gagnon

Level 37 , Tampa, United States

20 July 2023, 00:51

The equals() method is in the Object class, which is the base class that all other classes descend from. The Object class has the equals() method as well as getClass(), toString(), hashCode(), and more. So even though your code didn't have an explicit equals() method in it to overload, it is implicitly inherited from the Object class and therefore is being overloaded.