title: Exception in thread "main" java.lang.NumberFormatException: empty String FloatingDecimal & parseDouble
body: <p>I am getting an error. For some reason the error isn't showing up when I compile the code:</p>
  
  <p>//This is the error I get
      Exception in thread "main" java.lang.NumberFormatException: empty String
      at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1842)
      at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)
      at java.lang.Double.parseDouble(Double.java:538)
      at Project3A.main(Project3A.java:42)</p>
  
  <pre><code>    //Code starts here
      import java.util.scanner;
      import javax.swing.JOptionPane;
      import java.text.DecimalFormat;
      import java.util.Locate;
      import java.text.NumberFormat;
  
          public class Project3A
          {
               public static void main(String[] args)
               {
        int numloaves = 0;
        int nummilk = 0;
        double lbscheese = 0.00;
        double brdperloaf = 1.50;
        double milkperqrt = 1.00;
        double chseperlbs = 0.50;
        NumberFormat moneyFormat = NumberFormat.getCurrencyInstance(Locale.US);
  
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter the number of loaves of bread: ");
        int numloaves = sc.nextInt();
  
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter the number of quarts of milk: ");
        int nummilk = sc.nextInt();
  
        Scanner sc = new Scanner(System.in);
        System.ot.println("Enter the number of pounds of cheese: ");
        int chseperlbs = sc.nextInt();
  
        double brdcst = (numloaves * brdperloaves);
        double mlkcst = (nummilk * milkperqrt);
        double chsecst = (lbscheese * chseperlbs);
        double ttlcost = (brdcst + mlkcst + chsecst);
  
        String inputStr = JOptionPane.showInputDialog(null, "Enter number of apples");
        double value = Double.parseDouble(" ");
  
        System.out.println("Cost of Bread: " + brdcst);
        System.out.println("Cost of Milk: " + mlkcst);
        System.out.println("Cost of Cheese: " + chsecst);
  
        double d = 1.234567;
        DecimalFormat df = new DecimalFormat("#.##");
        JOptionPane.showMessageDialog(null, "Total Cost of bread, milk and cheese is " + df.format(d));
        System.out.println(df.format(d));
        }
  }
  </code></pre>