Untitled

1
package arraylistprogram;

import java.util.ArrayList;

import java.util.Collections;
public class sample {
 public static void main(String[] args) { // Creating an ArrayList
 ArrayList<Integer> numbers = new ArrayList<Integer>(); // Adding elements to the ArrayList
 numbers.add(5);
 numbers.add(2);
 numbers.add(7);
 numbers.add(3);
 numbers.add(1);
 // Removing an element from the ArrayList
 System.out.println("ArrayList after adding elements: " + numbers); 
 numbers.remove(2); // Removes the element at index 2
 // Sorting the elements of the ArrayList
 System.out.println("ArrayList after removing element at index 2: " + numbers); 
 Collections.sort(numbers);
 // Converting ArrayList to Array using toArray() method
 System.out.println("ArrayList after sorting: " + numbers); 
 Integer[] numbersArray = numbers.toArray(new Integer[numbers.size()]);
 System.out.println("Array after converting from ArrayList: ");
 for (Integer num : numbersArray) {
 System.out.print(num + " ");
 }
 }
}


2
package comparatorprogram;
import java.util.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;
import java.util.Scanner;
class TensPlaceComparator implements Comparator<Integer> {
 public int compare(Integer num1, Integer num2) {
 int tensPlace1 = (num1 % 100) / 10;
 int tensPlace2 = (num2 % 100) / 10;
 return Integer.compare(tensPlace1, tensPlace2);
 }
}
public class RandomNumbersSort {
 public static void main(String[] args) {
 Scanner scanner = new Scanner(System.in);
 System.out.print("Enter the lower bound of the range: ");
 int lowerBound = scanner.nextInt();
 System.out.print("Enter the upper bound of the range: ");
 int upperBound = scanner.nextInt();
 System.out.print("Enter the number of random numbers to generate: ");
 int count = scanner.nextInt();
List<Integer> randomNumbers = generateRandomNumbers(lowerBound, upperBound, 
count);
 System.out.println(randomNumbers);
 Collections.sort(randomNumbers, new TensPlaceComparator());
 System.out.println("\nSorted Numbers According to Tens Place:");
 for (int num : randomNumbers) {
 System.out.println(num);
 }
 
 scanner.close();
}

 private static List<Integer> generateRandomNumbers(int lowerBound, int upperBound, int count) {

 List<Integer> randomNumbers = new ArrayList<>();
 Random rand = new Random();
 int num;
 
 int i=0;
 while(i<count) {
 num = rand.nextInt(upperBound - lowerBound + 1) + lowerBound;
 if (num % 2 == 0 && num % 5 == 0) {
 randomNumbers.add(num);
 i++;
 }
 }
 
 return randomNumbers;
 }
}


3

import java.util.ArrayList;

import java.util.List;
class Person {
 private String name;
 private int age;
 public Person(String name, int age) {
 this.name = name;
 this.age = age;
 }
 public String getName() {
 return name;
 }
 public int getAge() {
 return age;
 }
 @Override
 public String toString() {
 return "{" +
 "name='" + name + '\'' +
 ", age=" + age +
 '}';
 }
}
public class Main {
 public static void main(String[] args) {
 // Create a list to store Person objects
 List<Person> personList = new ArrayList<>();
// Adding some Person objects to the list

 personList.add(new Person("Alice", 30));

 personList.add(new Person("Bob", 25));
 personList.add(new Person("Charlie", 35));
 // Displaying the contents of the list
 System.out.println("List of Persons:");
 for (Person person : personList) {
 System.out.println(person);
 }
 }
}