Project Euler

[Mathismylove]

Hi.

Im new to Java and attempted to increase my knowledge by working on Project Euler..I figured that If Im able to solve as many problems from the project as possible with Java I will get more familiar with its syntax and the possibilities that lie therein...
Im in problem no 1

Problem no 1:

Find the sum of numbers between 0 and 1000 that are divisible by 3 or 5 and display it


and here's my code.

mport java.lang.String;
import java.io.*;


public class ProjectEuler {
    
    public static void main(String[] args) {
    	
    int sum, counter, temp;
    	for( counter = 0; counter < 1000; counter ++)

          while (((counter % 3) == 0) | ((counter % 5) == 0))
              {
                sum = 0;
                temp = 0;
                temp = counter;
                sum = sum + temp;
              }

    System.out.println( "The sum of the numbers is: " +  sum);

The error that I keep getting is:

variable sum might not have been initialized

[RedSon]

You must put code tags around your code. Please do not forget to do it again.

[RedSon]

You need to initialize sum outside of the while loop. What happens if counter mod 3 or 5 is never equal to zero?

[Mathismylove]

sorry but i don't understand what you mean by putting tags. About your other question. If counter mod 3 or 5 is not equal to zero then counter is not assigned to temp and hence is not included in the sum of the variables. Unless I'm missing something. Thanks.

[RedSon]

Read the forum help pages if you don't understand about code tags. As for the other bit, the compiler is telling you that the sum variable needs to be set before entering the loop. You can still reset it in the loop, but the compiler can't figure out exactly what you are doing. All it sees is that you are using a variable that has not been initialized in a loop which may or may not be iterated through.

[Mathismylove]

i adjusted my code to have the sum initialized outside the for loop(before it actually!), but still I can't see any output on the output window. Its building and compiling without errors but its not giving me any output...
Maybe I should create an applet to display the output but I dont even know how to do that. What am I missing?

[RedSon]

You need to reexamine your loops.

What happens to your loops when counter is zero?

[Time]

Once your counter variable satisfies the while loop condition; no other condition provided for the loop to break; come out of itself.

[Mathismylove]

interesting insights guys..thanks redson and time...im on it!