Double.parseDouble Troubles

[Kara Wilimas]

Hello,

I am doing an assignment for my Java class.
It asks to 1) Read input from a user. 2) convert the input to a double number if valid 3) find average.
I am trying to convert the String entered by user into a double number using Double.parseDouble.

import java.util.*;
public class Grades{
   public static void main(String arg[]){ 
     
      
      int icount = 0;
      final int SIZE = 100;
      
      Scanner reader = new Scanner(System.in);
      String sInput = new String ("");
      String [] sSize = new String[SIZE];
      
      double count = 0; 
      boolean exit = false;
      
      System.out.println("You may enter 0-100 values."); 
      System.out.println("When you are done entering values, press enter/return key");
           
       
       
      while((count < SIZE)&&(exit == false)){ 
         System.out.println("Enter line " + (icount+1) + ": "); 
         sInput = reader.nextLine();
      if (sInput.length()<1){ 
         exit = true; 
      }
      else{
         double count = Double.parseDouble(String sInput);
          
         
      }
      }
   }
} 

[Kara Wilimas]

Apologies, forgot to mention that these errors occur:

Grades.java:29: error: ')' expected
double count = Double.parseDouble(String sInput);
^
Grades.java:29: error: illegal start of expression
double count = Double.parseDouble(String sInput);
^

[Jesper de Jong]

You already declared a variable named count in line 13. You can't declare another variable with the same name again in the same method, which is what you are doing in line 28 - you are declaring a new variable called count there.

Probably you just wanted to assign a value to the existing variable, instead of declaring a new variable. If that's what you wanted to do, then remove the type name double in line 28.

[Kara Wilimas]

Hello,

Thank you. I think I have it sorted now.

[Campbell Ritchie]

Never use == false or == true. Not only are they poor style, but they are prone to your writing = by mistake in which case you might get two errors for the price of one.
Not b == false but !b
Not b == true but simply b

[Campbell Ritchie]

Stop using Double.parseDouble unless you are sure the text will be in the correct format for a double.
Find out about the methods of the Scanner class.