How to make a thread wait until another thread finishes?

Need help in java! "reached end of file while parsing"?

• ok so i just started learning java tonight and was doing one of the projects in the book I'm learning from "programming video games for the evil genius" as i finished the project I kept trying to close the brackets but it kept saying "while expecting" and " reached end of file while parsing" I've re read the code and the book 6 times and i can't find the mistake. Any help would be really appreciated. Heres the code. The program is a maths flash card game. it randomly generates a simple sum and it gives you a set amount of time to figure out the answer //first, allow for input getting import javax.swing.*; //create a class named S1P4 public class S1P4 { private static int sign; //main method (throws Exception) added for Thread.sleep() public static void main (String[] args) throws Exception { //this will be how many 1/2 seconds the user gets int difficulty; difficulty = Integer.parseInt(JOptionPane.showInputDi… good are you?\n"+ "1 = Genius..\n"+"10 = Retart")); //this will tell the loop whether to continue or not: boolean cont = false; //the contents of the main method are about to be enclosed in a // do while loop... do { //reset cont to false cont = false; //random numbers for the equation double num1 = (int)(Math.round(Math.random()*10)); //this do..while loop prevents exceptions. num2 mustbe //declared outside of the do while so the "while" part can //see it. It will still be initialized inside the do part, //thought double num2; { //init num2 num2 = (int)(Math.round(Math.random()*3)); //will store answer double answer; //make stuff noticable System.out.println("\n\n*****"); if(sign==0) { //tell user and calculate answer System.out.println(num1+"times"+num2); answer = num1*num2; } else if(sign==1) { //tell user and calculate answer System.out.println(num1+"divided by"+num2); answer = num1/num2; } else if(sign==1) { //tell user answer and calculate System.out.println(num1+"plus"+num2); answer = num1+num2; } else if(sign==1) { //tell user answer and calculate System.out.println(num1+"minus"+num2); answer = num1-num2; } else { //tell user and calculate answer System.out.println(num1+"%"+num2); answer = num1%num2; } //make it easier to read... System.out.println("*****\n"); //count down from difficulty... use for a loop! for(int i = difficulty;i>=0;i--) { //count down at double speed! System.out.println(i+"..."); //instead of waiting a second. this time only //wait 1/2 a second per difficulty level Thread.sleep(500); } //print answer System.out.println("ANSWER:"+answer); //ask if they want to play again String again; again=JOptionPane.showInputDialog("Pla… again?"); //if user says yes set cont=true if(again.equals("yes")) cont = true; } while(cont); } }

• Answer:

  I'm not not sure what that code is supposed to do, but no matter, it appears your problem is at the end: if(again.equals("yes")) cont = true; } while(cont); } } you have no opening bracket for your if! Not sure what the double brackets after the while are supposed to accomplish though.