how to take the result from the loop into string with index?

Question

I am trying to build a string, and put the result of the loop "att" into string with the index "i". So, I can sort the string and output the highest attendance school with the school number. Thanks!

import java.util.Scanner;

public class PengjuShanP1 {

    public static void main(String[] args) {
        Scanner scnr = new Scanner(System.in);
        System.out.print("How many schools do you have in your district: ");
        int nos = scnr.nextInt();
        int[] nums = new int[nos];
        System.out.println();

        double ax  = 0;

        for (int i = 1; i < nos + 1; ++i) {
             System.out.println("Enter data for school " + i);
             System.out.print("   How many students are enrolled in school : ");
             int num = scnr.nextInt();



             System.out.print("   Enter the attendance for day 1: ");
             int d1 = scnr.nextInt();


             System.out.print("   Enter the attendance for day 2: ");
             int d2 = scnr.nextInt();

             System.out.print("   Enter the attendance for day 3: ");
             int d3 = scnr.nextInt();

             System.out.print("   Enter the attendance for day 4: ");
             int d4 = scnr.nextInt();

             System.out.print("   Enter the attendance for day 5: ");
             int d5 = scnr.nextInt();

             double avg = ((d1 + d2 + d3 + d4 + d5) / 5) * 100;
             double att = avg / num;
             ax = att + ax;

             System.out.println();

             System.out.println("Attendance " + att + "% for school " + i);
             System.out.println();
        }
        System.out.print(ax);
    }
}

Answer 1

The question is not clear and array index always start from zero instead of 1 as mentioned in the for loop. if you are looking to store att in array of String, declare String array and store att in the string array

Answer 2

EDIT

Given that the school id is an integer, it's possible to do this in a simple array, which is more space and time efficient than the collections API below.

Initialize a double array early on:

double[] schools = new double[nos];

Add data in the loop:

schools[i] = att;

And find the highest at the end, with printing:

double highest = 0;
int index = 0;
for (int i = 0; i < schools.length; i++)
{
  if (schools[i] > highest)
  {
    index = i;
    highest = schools[i];
  }
}
System.out.println("The school with the best attendance is school " + (index + 1) + " with " + highest + "% attendance");

The full example:

import java.util.Scanner;

public class ValuePairSortingSimpler
{
  public static void main(String[] args)
  {
    Scanner scnr = new Scanner(System.in);
    System.out.print("How many schools do you have in your district: ");
    int nos = scnr.nextInt();
    double[] schools = new double[nos];
    System.out.println();

    double ax = 0;

    for (int i = 0; i < nos; i++)
    {
      System.out.println("Enter data for school " + (i + 1));
      System.out.print("   How many students are enrolled in school : ");
      int num = scnr.nextInt();

      System.out.print("   Enter the attendance for day 1: ");
      int d1 = scnr.nextInt();

      System.out.print("   Enter the attendance for day 2: ");
      int d2 = scnr.nextInt();

      System.out.print("   Enter the attendance for day 3: ");
      int d3 = scnr.nextInt();

      System.out.print("   Enter the attendance for day 4: ");
      int d4 = scnr.nextInt();

      System.out.print("   Enter the attendance for day 5: ");
      int d5 = scnr.nextInt();

      double avg = ((d1 + d2 + d3 + d4 + d5) / 5) * 100;
      double att = avg / num;
      schools[i] = att;
      ax = att + ax;

      System.out.println();

      System.out.println("Attendance " + att + "% for school " + (i + 1));
      System.out.println();
    }
    double highest = 0;
    int index = 0;
    for (int i = 0; i < schools.length; i++)
    {
      if (schools[i] > highest)
      {
        index = i;
        highest = schools[i];
      }
    }
    System.out.println("The school with the best attendance is school " + (index + 1) + " with " + highest + "% attendance");
    System.out.print(ax);
  }
}

Original Post:

I'm not sure a string is the best route here. If I'm not mistaken, you'd like to store several pairs of values in a list or array and then sort that by one of the values. That problem is best solved using the collections API. For an example:

Define a list of key-value pairs at the beginning (before the loop). The key will be the school id and the value will be the attendance.

List<Map.Entry<Integer, Double>> schools = new ArrayList<>();

Then add the data to the list in the loop:

schools.add(Map.entry(i, att));

And at the end, sort it descending by value (highest first), then print the results.

schools.sort((a,b)->(int)Math.round(b.getValue()-a.getValue()));
System.out.println("The school with best attendance is school " + schools.get(0).getKey() + " with " + schools.get(0).getValue() + "% attendance!");

A full example follows:

  public static void main(String[] args)
  {
    Scanner scnr = new Scanner(System.in);
    System.out.print("How many schools do you have in your district: ");
    int nos = scnr.nextInt();
    List<Map.Entry<Integer, Double>> schools = new ArrayList<>();
    System.out.println();

    double ax = 0;

    for (int i = 1; i < nos + 1; ++i)
    {
      System.out.println("Enter data for school " + i);
      System.out.print("   How many students are enrolled in school : ");
      int num = scnr.nextInt();

      System.out.print("   Enter the attendance for day 1: ");
      int d1 = scnr.nextInt();

      System.out.print("   Enter the attendance for day 2: ");
      int d2 = scnr.nextInt();

      System.out.print("   Enter the attendance for day 3: ");
      int d3 = scnr.nextInt();

      System.out.print("   Enter the attendance for day 4: ");
      int d4 = scnr.nextInt();

      System.out.print("   Enter the attendance for day 5: ");
      int d5 = scnr.nextInt();

      double avg = ((d1 + d2 + d3 + d4 + d5) / 5) * 100;
      double att = avg / num;

      schools.add(Map.entry(i, att));

      ax = att + ax;

      System.out.println();

      System.out.println("Attendance " + att + "% for school " + i);
      System.out.println();
    }
    System.out.print(ax);
    schools.sort((a,b)->(int)Math.round(b.getValue()-a.getValue()));
    System.out.println("The school with best attendance is school " + schools.get(0).getKey() + " with " + schools.get(0).getValue() + "% attendance!");
  }