Question

my issue is in my “NumberAnalyzer.java” class, I’m supposed to be able to use the “Number.java” class to determine if a number from the ArrayList is odd (as well as even and perfect later on) but since the “isOdd()” method in “Number.java” doesn’t read in an int or other variable itself, I can’t find a way to test each number to make “oddCount” in the “countOdds” method of “NumberAnalyzer.java” increase to produce the number of odd numbers in the string from the runner class.

NumberAnalyzer.java

import java.util.ArrayList;
import java.util.Scanner;

import com.sun.xml.internal.ws.api.pipe.NextAction;

import static java.lang.System.*;

public class NumberAnalyzer
{
private ArrayList<Number> list;

public NumberAnalyzer()
{

}

public NumberAnalyzer(String numbers)
{
    list = new ArrayList<Number>();
    String nums = numbers;
    Scanner chopper = new Scanner(nums);
    while(chopper.hasNext()){
        int num = chopper.nextInt();
        list.add(new Number(num));
    }
    chopper.close();
    System.out.println(list);
}

public void setList(String numbers)
{
    list = new ArrayList<Number>();
    String nums = numbers;
    Scanner chopper = new Scanner(nums);
    while(chopper.hasNext()){
        int num = chopper.nextInt();
        list.add(new Number(num));
    }
    chopper.close();

}

public int countOdds()
{
  int oddCount=0;
  for(int i = 0; i < list.size(); i++){
      if(Number.isOdd()== true){
          oddCount++;
      }
  }
  return oddCount;
}

public int countEvens()
{
  int evenCount=0;



  return evenCount;
}

public int countPerfects()
{
    int perfectCount=0;



  return perfectCount;
}

public String toString( )
{
    return "";
}
}

Number.java

public class Number
{
private Integer number;

public Number()
{


}

public Number(int num)
{
    number = num;
}

public void setNumber(int num)
{
    number = num;
}

public int getNumber()
{
    return number;
}   

public boolean isOdd()
{
    if(number%2==0){
        return false;
    }
    return true;
}

public boolean isPerfect()
{
    int total=0;
    for(int i = 1; i < number; i++){
        if(number%i==0){
            total+= i;
        }
    }


    return (number==total);
}   

public String toString( )
{
    String output = getNumber() + "\n" + getNumber()+ "isOdd == " + isOdd() + "\n" + getNumber()+ "isPerfect==" + isPerfect()+ "\n\n";
    return output;
}
}

runner class

import java.util.ArrayList;
import java.util.Scanner;
import static java.lang.System.*;

public class Lab16b
{
public static void main( String args[] )
{
    NumberAnalyzer test = new NumberAnalyzer("5 12 9 6 1 4 8 6");
    out.println(test);
    out.println("odd count = "+test.countOdds());
    out.println("even count = "+test.countEvens());
    out.println("perfect count = "+test.countPerfects()+"\n\n\n");


    //add more test cases


}
}

Answer 1

When you call

test.countOdds());

control goes to NumberAnalyzer.java

public int countOdds()
{
  int oddCount=0;
  for(int i = 0; i < list.size(); i++){
      if(Number.isOdd()== true){
          oddCount++;
      }
  }
  return oddCount;
}

And here you are calling Number.isOdd() method by Class name as a static way but i do not think you can do this way because isOdd() is not static.

It is compile time error

Solution:

Iterate your list and send value one by one from the list to isOdd(int val) method.

Try to make isOdd() method static which accept one numeric parameter and will return true or false.

increase your counter based on return type as you do.