error: cannot find symbol superclass and subclass

Question

I am a beginner in java and I am trying to write a java code where the program has to calculate the arithmetic mean in the superclass and standard deviation in the subclass.

Here is my code:

import java.util.*;
class ArithmeticMean
{
    double  sum=0, mean, variance, sd, vsum;
    double a[] = new double[10];
    int n,i;
    void accept()
    {
        Scanner scanner = new Scanner(System.in);
        System.out.println("How many Numbers do you want to enter?");
        n=scanner.nextInt();

        for(i=0; i<n; i++)
        {
            System.out.println("Enter No ["+(i+1)+"] : ");
            a[i] = scanner.nextInt();
        }       
    }
    void calculate()
    {
        for(i=0; i<n; i++)
        {
            sum = sum + a[i];
            mean = sum/n;
        }
    }
}
class StandardDeviation extends ArithmeticMean
{
    void calculateSd()
    {
        for(i=0; i<n; i++)
        {
            vsum = vsum+((a[i]-mean)*(a[i]-mean));
            variance = vsum/(n-1);
            sd=Math.sqrt(variance);
        }
    }
    void display()
    {
        System.out.println("Arithmetic mean = "+mean);
        System.out.println("Variance = "+variance);
        System.out.println("Standard Deviation = "+sd);
    }
}
class u3Program9
{
    public static void main(String args[])
    {
        StandardDeviation s = new StandardDeviation();
        s.accept();
        s.calculate();
        s.calculateSD();
        s.display();
    }
}

Here is the error I'm getting:

You should Use some IDE like eclipse to write program such type of syntex error wont occur. — black_pottery_beauty, Mar 30 '18 at 05:58
https://stackoverflow.com/questions/25706216/what-does-a-cannot-find-symbol-compilation-error-mean — Stephen C, Mar 30 '18 at 07:12

score 1 · Answer 1 · answered Mar 30 '18 at 05:48

1

Java is case-sensitive programming language.

You have defined calculateSd() in StandardDeviation class and invoking calculateSD() on instance of StandardDeviation s.calculateSD(). Where it should be accesed as s.calculateSd()

answered Mar 30 '18 at 05:48

Sagar Pudi

4,634
3
32
51

MinA · Answer 2 · 2018-03-30T05:56:16.000

1

your method is declared as calculateSd,

in your main method change

s.calculateSD();

to

s.calculateSd();

edited Mar 30 '18 at 05:56

answered Mar 30 '18 at 05:54

MinA

405
4
9

score 0 · Answer 3 · answered Mar 30 '18 at 05:51

0

You failed type method name. Your method in StandardDeviation class: calculateSd. You invoke method: calculateSD.

You need rewrite method number to upper or lower case.

answered Mar 30 '18 at 05:51

Jaleary

1
2

score 0 · Answer 4 · answered Mar 30 '18 at 05:51

0

The error message says that it cannot find the symbol named 'calculateSD()' in s of StandardDeviation class.

That gives a clue. The method is defined as 'calculateSd()' in StandardDeviation.class, with the lower-case 'd' in the back.

answered Mar 30 '18 at 05:51

enadiz

23
5

error: cannot find symbol superclass and subclass

4 Answers4