public class Main { public static void main(String[] args) { System.out.println("Hello" + "world!"); System.out.println("Hello " + "world!"); System.out.println("Hello"); System.out.println("world!"); System.out.print("Hello"); System.out.println(" world!"); System.out.println("3 + 4 = " + 3 + 4); System.out.println("3 + 4 = " + (3 + 4)); System.out.println("3 - 4 = " + (3 - 4)); System.out.println("3 * 4 = " + (3 * 4)); System.out.println("7 / 3 = " + (7 / 3)); System.out.println("7 % 3 = " + (7 % 3)); int radius; // Αυτό είναι ένα σχόλιο μιας γραμμής /* * Αυτό είναι ένα σχόλιο * πολλαπλών γραμμών. */ int radius1; } }