CODEWITHSUNDEEP
javaincompatibletypeerror
Matthew Optional Meehan
Matthew Optional Meehan

Reputation: 745

Incompatible types on method

import java.util.*;
import java.lang.Math;

class StandardDeviation{
  public static void main(String args[]){
    ArrayList<Double> numbers = new ArrayList<Double>();
    Scanner kb=new Scanner(System.in);
    double in=kb.nextDouble();
    while(in!=-1){
        numbers.add(kb.nextDouble()); 
    }
    double avg = getAvg(numbers);
    double stdD = getD(avg,numbers);// tells me these are incompatible types
    System.out.printf("%f\n",stdD);
  }

  public static double getAvg(ArrayList<Double> numbers){
    double sum = 0.0;
    for (Double num : numbers){
        sum+= num;
    }
    return sum/numbers.size();
  }

  public static void getD(double avg, ArrayList<Double> numbers){
    ArrayList<Double> newSet = new ArrayList<Double>();
    for (int i = 0; i < numbers.size(); i++){
        newSet.add(Math.pow(numbers.get(i)-avg,2));
    }
    double total = 0.0;
    for (Double num : newSet){
        total += num;
    }
    double mean =(total/numbers.size());
    return Math.sqrt(mean);
  }
}

Im so tired and I got this far into this exercise, I'm not even sure if it prints out the correct answer but right now its telling me double stdD = getD(avg,numbers); that there are incompatible types, not sure what is incompatible Thanks in advance

Upvotes: 0

Views: 652

Answers (2)

Pramod Kumar
Pramod Kumar

Reputation: 8014

Your method is not returning anything. method return type is void and you are assigning that into double. that's why you are getting an error. Your method declaration should be like this - 

public static double getD(double avg, ArrayList<Double> numbers)

Upvotes: 3

tagtraeumer
tagtraeumer

Reputation: 1491

getD is void, it doesn't return a value. It's currently

public static void getD(double avg, ArrayList<Double> numbers){

but it should probably be

public static double getD(double avg, ArrayList<Double> numbers){

Upvotes: 6

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