Question

import java.util.Scanner;

public class EP55Out
{

    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);    
        System.out.print("Please enter a grade: ");
        String letter = in.next();
//         getNumericGrade(grade);
    }
    public static void getNumericGrade(double grade)
    {
        int spacer = 0;
        String first = letter.substring(0,1);
        String second = letter.substring(1,2);

        if (first.equalsIgnoreCase("a"))
        grade = 4.0;
        else if (first.equalsIgnoreCase("b"))
        grade = 3.0;
        else if (first.equalsIgnoreCase("c"))
        grade = 2.0;
        else if (first.equalsIgnoreCase("d"))
        grade = 1.0;
        else if (first.equalsIgnoreCase("f"))
        grade = 0;
        else grade = 9;

        if (second.equalsIgnoreCase("+"))
        grade += 0.3;
        else if (second.equalsIgnoreCase("-"))
        grade -= 0.3;
        else
        grade += 9;
        System.out.println(grade);
    }
}

I don’t know if you guys understand what I mean, but I keep getting the error that “grade” does not exist even though it is defined in the main. I know it has something to do with “void” but I have no clue what. Can anybody help?

Answer 1

So you are learning Java don’t you?

I’ll try to explain what you are doing wrong.

import java.util.Scanner;

public class EP55Out {

    public static void main(String[] args){
        Scanner in = new Scanner(System.in);    
        System.out.print("Please enter a grade: ");
        String letter = in.next();
        //You need to give letter to the method
        getNumericGrade(letter);
    }

    //AND the method should need String and not double 
    public static void getNumericGrade(String letter){      
    //After this you need a real double value - lets call is grade;
        double grade = 0;
        int spacer = 0;
        String first = letter.substring(0,1);
        String second = letter.substring(1,2);

        //You cant to numeric stuff with a String- thats why we use our double here
        if (first.equalsIgnoreCase("a"))
        grade = 4.0;
        else if (first.equalsIgnoreCase("b"))
        grade = 3.0;
        else if (first.equalsIgnoreCase("c"))
        grade = 2.0;
        else if (first.equalsIgnoreCase("d"))
        grade = 1.0;
        else if (first.equalsIgnoreCase("f"))
        grade = 0;
        else grade = 9;

        if (second.equalsIgnoreCase("+"))
        grade += 0.3;
        else if (second.equalsIgnoreCase("-"))
        grade -= 0.3;
        else
        grade += 9;
        System.out.println(grade+"");
    }
}

You missed an important point with variables…
If you define a variable in a method – it is only visible in THE DEFINING METHOD!

So
public static void getNumericGrade(String letter)
cannot know that there is a letter variable in
public static void main(String[] args)

Hope I could help you 😉