How to get rid of the 'cannot find symbol' errors in my code?

Question

I am currently working on a project and i keep getting error messages. I am stuck and have contacted many people (including my instructor), and I have now turned to you guys.

Here is my code so far.

public class Circle

    private int radius = getRadius();
    private double area = getArea();

    public Circle(int r) 
    {
        r = radius;
    }

    public int getRadius()
    {
        return radius;
    }

    public double getArea(int r)
    {
        return area = Math.PI * r * r;  
    }
}

/

java.util.Scanner;

public class CircleTest
{
    public CircleTest()
    {
        int radius = getRadius();
        double area = getArea(r);       
    }   

    public static void main (String[] args) 
    {

        Scanner kboard = new Scanner(System.in);

        System.out.print("Give the radius of a circle. ");
        String area = kboard.nextLine();

        System.out.println("The area of the circle is... " + 
area);
        System.out.println();

        kboard.close();
    }
}

C:\Users\jthom\My Work\Circle\src\CircleTest.java:18: error: cannot find symbol

double area = getArea(r);

symbol: variable r

location: class CircleTest

.

C:\Users\jthom\My Work\Circle\src\CircleTest.java:33: error: cannot find symbol

System.out.println("The area of the circle is... " + area);

symbol: variable area

location: class CircleTest

2 errors

Looks like CircleTest should extend Circle or you should create create instance of Circle object — user51, Mar 06 '19 at 18:31
Your errors are so basic I question you have consulted anyone. These are simple compilation errors, what is it you don’t understand about them? — Joakim Danielson, Mar 06 '19 at 18:34

score 5 · Accepted Answer · answered Mar 06 '19 at 18:58

Let's start with class Circle. This is your original code:

public class Circle

    private int radius = getRadius();
    private double area = getArea();

    public Circle(int r) 
    {
        r = radius;
    }

    public int getRadius()
    {
        return radius;
    }

    public double getArea(int r)
    {
        return area = Math.PI * r * r;  
    }

}

For your variables, you don't need "area", as it is calculated. Also, you shouldn't be assigning radius to anything except in the constructor:

    private int radius;
    //private double area = getArea(); <-- don't need this variable at all

You pass in "r" to the constructor, but then incorrectly try to assign the "radius" value to it. This is backwards; you should be assigning the "r" value to "radius" instead:

    public Circle(int r) 
    {
        radius = r;
    }

Finally, in getArea(), you don't need the radius passed in, or "area"; just return the calculated value (using the stored value in "radius", not "r"):

    public double getArea()
    {
        return Math.PI * radius * radius;  
    }

Put all together, your Circle class should look more like:

public class Circle

    private int radius;

    public Circle(int r) 
    {
        radius = r;
    }

    public int getRadius()
    {
        return radius;
    }

    public double getArea()
    {
        return Math.PI * radius * radius;  
    }

}

Over in CircleTest, you should first get the radius from the user, then pass that to the constructor of Circle. Finally, with your instance of Circle, call its getRadius() and getArea() methods.

Akash Jain · Answer 2 · 2019-03-06T19:20:03.093

-1

You have not defined variable r and area ,to help solve this

replace double area = getArea(r); to double area = circle.getArea(radius);

and

System.out.println("The area of the circle is... " + area); with System.out.println("The area of the circle is... " + circle.getArea(Integer.parseInt(area)));

here the circle is an object of Class circle

Circle circle = new Circle(radius) //Note: circle cannot be accessed from main function create another object for class circle again in main

it should help

edit: here is link about the error What does a "Cannot find symbol" compilation error mean?

edited Mar 06 '19 at 19:20

answered Mar 06 '19 at 18:34

Akash Jain

684
9
23

Both uses of getArea yes – Joakim Danielson Mar 06 '19 at 19:06
2

There is no method getArea to call and nothing called Initger and while the last is most likely a typo is it to much to ask that you compile the code you put in your answer? – Joakim Danielson Mar 06 '19 at 19:11
2

I got tired of correcting your code for you. Think about what code you are posting and what it really does – Joakim Danielson Mar 06 '19 at 19:25

How to get rid of the 'cannot find symbol' errors in my code?

2 Answers2