title: required int found no argument reason actual and formal argument lists differ in length
body: <pre><code>import java.lang.Math;
  import javax.swing.JOptionPane;
  
  public class IntegerNumber
  {
          //declaring main variable used throughout the whole code
  
      public static void main(String[] args)
      {
          //declare variable
          int menuNumber;
  
          String input = JOptionPane.showInputDialog("Select What You want to do: \n1: Calculate the total of the squares of the first inputted natural numbers. \n 2: Get the mean of the first N odd natural numbers. \n 3: Determine if the inputted number is a prime number. \n 4: Return a Fibonacci number. \n 5: Exit Program.");
          menuNumber = Integer.parseInt(input);
          if (menuNumber == 1)
          {
              TotalSquares();
          }
          else if (menuNumber == 2)
          {
              OddNumberMean();
          }
          else if (menuNumber == 3)
          {
              PrimeNumber();
          }
          else if (menuNumber == 4)
          {
              FibonacciNumber();
          }
          else if (menuNumber == 5)
          {
              System.exit(0);
          }
  
  
  
      }
  
  public static double TotalSquares()
      {
          int N;
          double total;
          int k;
                      String input = JOptionPane.showInputDialog("Enter a number between 1 and 20 to find the total squared numbers of");
              N = Integer.parseInt(input);
  
              total = 0;
              for(k=1; k&lt;=N; k++);
                  total +=(k*k);
              return total;
              System.out.println("Your total is = " + total);
  
  
      }
  public static double OddNumberMean()
  {
      int N;
      int i;
      String input = JOptionPane.showInputDialog("Enter a number between 1 and 50 to find the mean of the odd numbers");
      N = Integer.parseInt(input);
      double total = 0;
      for(i=0;i&lt;=N; i++);
      { total+= 2*i +1;};
      System.out.println("The mean is = " + (total/N));
  }
  
  public static double PrimeNumber()
  {
      int N;
      int g;
      String input = JOptionPane.showInputDialog("Enter a number between 2 and 200, determine whether or not the number is prime");
      N = Integer.parseInt(input);
              for (g = 2; g&lt;N; g++)
              {
              if (N % g == 0)
                  {
              System.out.println("The number is not prime");
                  }
              }
              System.out.println("The number is prime");
  
  
  }
  
  
  public static int FibonacciNumber(int N)
  {
      String input = JOptionPane.showInputDialog("Compute and return a Fibonacci number");
      N = Integer.parseInt(input);
  
          if (N==0)
              return 0;
          else if(N==1)
              return 1;
          else
              return FibonacciNumber(N-1) + FibonacciNumber(N-2);
  
  
  }
  
  }
  </code></pre>
  
  <p>I keep getting this error:</p>
  
  <pre><code>IntegerNumber.java:33: error: method FibonacciNumber in class
  IntegerNumber cannot be applied to given types;              
  FibonacciNumber();
                  ^   required: int   found: no arguments   reason: actual and formal
  argument lists differ in length
  </code></pre>
  
  <p>and I can not find a way to fix it. Any help appreciated as I can't seem to find the answer on other posts.</p>