Question

Create a class named "Laptop". In the following class, there are four instance variables. Name (type string), brand (type string), model_number (type string), and menefactureing_year (type int). Create a class named "LaptopMain" and the following class adds some data into the ArrayList. The type of ArrayList is Laptop. Now, write a java program to compare the values based on the name and menefatureing_year then print the value in the console.

Answer 1

```java

// Create Laptop and LaptopMain classes, add data to ArrayList, and compare/sort by name and manufacturing year.

Collections.sort(laptops, Comparator.comparing(Laptop::getName).thenComparing(Laptop::getManufacturingYear));

```

Step-by-step explanation:

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

class Laptop {

String name, brand, model_number;

int manufacturing_year;

Laptop(String name, String brand, String model_number, int manufacturing_year) {

this.name = name;

this.brand = brand;

this.model_number = model_number;

this.manufacturing_year = manufacturing_year;

}

}

class LaptopMain {

public static void main(String[] args) {

ArrayList<Laptop> laptops = new ArrayList<>();

// Add data to the ArrayList here

// Compare based on name and manufacturing_year

Collections.sort(laptops, Comparator.comparing(Laptop::getName).thenComparing(Laptop::getManufacturingYear));

// Print the sorted values

for (Laptop laptop : laptops) {

System.out.println("Name: " + laptop.name + ", Manufacturing Year: " + laptop.manufacturing_year);

}

}

}

In this Java program, a class named `Laptop` is created with instance variables for name, brand, model number, and manufacturing year. Another class, `LaptopMain`, adds data to an ArrayList of type Laptop and then compares the values based on name and manufacturing year using the `Collections.sort` method with a custom comparator. The sorted values are then printed to the console.

This program demonstrates the use of classes, ArrayLists, and sorting based on multiple criteria in Java.