import java.util.Vector;
class StringExample {
    public static void main(String[] args) {
        String s = "Hello";
        System.out.println(s.toUpperCase());
        StringBuffer sb = new StringBuffer("Hi");
        sb.append(" Java");
        System.out.println(sb);
        Vector<String> v = new Vector<>();
        v.add("A"); 
        v.add("B");
        System.out.println(v);
    }
}