import java.util.ArrayList; public class CollectionExample { public static void main(String[] args) { ArrayList<String> list = new ArrayList<>(); list.add("Java"); list.add("Python"); list.add("C++"); System.out.println("List size: " + list.size()); for (String language : list) { System.out.println(language); } } } import java.io.*; public class FileIOExample { public static void main(String[] args) { try { BufferedReader reader = new BufferedReader(new FileReader("input.txt")); BufferedWriter writer = new BufferedWriter(new FileWriter("output.txt")); String line; while ((line = reader.readLine()) != null) { writer.write(line); writer.newLine(); } reader.close(); writer.close(); } catch (IOException e) { e.printStackTrace(); } } } public class ThreadExample { public static void main(String[] args) { Thread thread1 = new Thread(new MyRunnable()); Thread thread2 = new Thread(new MyRunnable()); thread1.start(); thread2.start(); } } class MyRunnable implements Runnable { @Override public void run() { for (int i = 0; i < 5; i++) { System.out.println(Thread.currentThread().getName() + ": " + i); } } }


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