import java.util.ArrayList; import java.util.Collections; public class SwapWithMe{ public static void main(String[] args) { ArrayList c1= new ArrayList(); c1.add("Mark Go"); c1.add("Nicasio Aliping Jr."); Duque"); c1.add("Edgardo c1.add("Rafael Wasan"); c1.add("Reynaldo Diaz Jr."); cl.add("Alexis Abano"); System.out.println("Array list before Swap: "); for (String a: c1) { System.out.println(a); } //Swapping the second element with the fourth element Collections.swap(c1, _); (ITEM #1) J list after swap: "); System.out.println("Array for (String b: c1){ System.out.println(b); } } }

form> <label for="username">Username <i>(letters and numbers only, no punctuation or special characters)</i></label><br> <input name="username" id="username" pattern="[A-Za-z0-9]+"> </form> What do the square brackets and plus sign (+) mean?