Thread: Having trouble completing tester class!

Originally Posted by bankoscarpa

This is the tester class.

import java.util.Scanner;
public class NumbersTester
{
 public static void main(String[] args)
    {
        String s = "";    
        Scanner in = new Scanner(System.in);
        System.out.print("Enter digits: ");
        int n = in.nextInt();
        s = Integer.toString(n);
        System.out.println(countDigits(s));
		Numbers s = new Numbers(int n);
	}
}

This is my other class:

import java.util.Scanner;
 
public class Numbers
{
private int n;
 public Numbers()
 {
	int n = intn;
 }
    }
 public static int countDigits(String s) 
    {
        int count = 0;
 
        for (int i = 0; i < s.length(); i++)
        {
            if (s.charAt(i) == '7') 
            {
                count++;
            }
        }
        return count;
    }
 
}

I am not sure what i am missing and would really appreciate help.

thank you!

System.out.println(countDigits(s));

There's no method called countDigits(s) in that class with the main method.

Try this

Number n = new Number();

System.out.println(n.countDigits(s));

I also don't see an intn as a variable anywhere in that Number class.

Also, it seems you have both a class variable n and a local variable n that's only visible inside your constructor.

You don't pass it the variable type with a reference parameter, only a declaration.

For instance, if you had a method

public int method (String variable, int number)

then you could call it with something like

method("Bla bla bla", 10);

You don't mention the param data types when calling a method.

Also, in this case, since that method is a static method, you can get away with using the class name without having to even make an object.

you could use, for instance

System.out.println(Number.countDigits(s));

However, that only works if the method is static.

Otherwise, you'll get an annoying error saying:

"non-static method [the method] cannot be referenced from a static context."

Also, it appears that you have an extra bracket after your Numbers constructor.

Anyway, Numbers isn't passed an int as a param anyway.