Question

I am trying to create a function in JAVA that takes in an ArrayList and sorts the values by their distance in miles in increasing order. So the closest (or lowest) value would be first.

It does not need to output the values in anyway, but it should return them so they can be output elsewhere.

Please try to use the stub class below.

The code for the main class is not necessary. I am only really asking for the formula code to sortByDistance. I do not want anything else.

public ArrayList sortByDistance(boolean increasing) {
       // can sort by distance increasing (true) or decreasing (false)
       return null;
   }

Answer 1

Here is the answer for your question in Java Programming Language.

Kindly upvote if you find the answer helpful.

NOTE : As you mentioned your function sortByDistance will take in ArrayList as parameter, you have to pass array list into the function. But I could see a boolean passed to the function. If you expect the function to sort according to the boolean value of increasing (i.e., if increasing is true,sorts in increasing order, if false, sorts in decreasing order)please find the below code.

Otherwise there is a buit-in function sort() that automatically sorts an arraylist arranging its elements in increasing order.

I will provide function implementation using sort() and without using sort(). Please comment below if you have any doubts.

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CODE :

Using sort()

import java.util.ArrayList; import java.util.Collections; public class SortArrayList {    public static void main(String[] args){ //Have taken distances as double values //Please change datatypes as per your requirements ArrayList<Double> distances = new ArrayList<>(); //Adding distance values to arraylist distances.add(90.5); distances.add(88.6); distances.add(190.6); distances.add(23.6); distances.add(48.6); distances.add(289.6);    //Call method with increasing as true SortArrayList obj = new SortArrayList(); obj.sortByDistance(distances, true); System.out.println("After sorting in increasing order : "); System.out.println(distances); System.out.println("====================================");    obj.sortByDistance(distances, false); System.out.println("After sorting in decreasing order : "); System.out.println(distances); System.out.println("===================================="); } //As we have to take array list as parameter,had to change the function prototype public ArrayList sortByDistance(ArrayList<Double> distances,boolean increasing) { // can sort by distance increasing (true) or decreasing (false) if(increasing){ Collections.sort(distances); }else{ double temp = distances.get(0); //Sorting in decreading order (if increasing is false) //NOTE : We cannot use sort() for decreasing order for(int i = 0;i<distances.size();i++){ for(int j = i+1;j<distances.size();j++){ if(distances.get(i) < distances.get(j)){ temp = distances.get(i); distances.set(i, distances.get(j)); distances.set(j,temp); } } } } return distances; } }

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SCREENSHOTS :

Please see the screenshots of the code below for the indentations of the code.

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Without using sort()

import java.util.ArrayList; import java.util.Collections; public class SortArrayList {    public static void main(String[] args){ //Have taken distances as double values //Please change datatypes as per your requirements ArrayList<Double> distances = new ArrayList<>(); //Adding distance values to arraylist distances.add(90.5); distances.add(88.6); distances.add(190.6); distances.add(23.6); distances.add(48.6); distances.add(289.6);    //Call method with increasing as true SortArrayList obj = new SortArrayList(); obj.sortByDistance(distances, true); System.out.println("After sorting in increasing order : "); System.out.println(distances); System.out.println("====================================");    obj.sortByDistance(distances, false); System.out.println("After sorting in decreasing order : "); System.out.println(distances); System.out.println("===================================="); } //As we have to take array list as parameter,had to change the function prototype public ArrayList sortByDistance(ArrayList<Double> distances,boolean increasing) { // can sort by distance increasing (true) or decreasing (false) double temp = distances.get(0); if(increasing){ for(int i = 0;i<distances.size();i++){ for(int j = i+1;j<distances.size();j++){ if(distances.get(i) > distances.get(j)){ temp = distances.get(i); distances.set(i, distances.get(j)); distances.set(j,temp); } } } }else{ //Sorting in decreading order (if increasing is false) //NOTE : We cannot use sort() for decreasing order for(int i = 0;i<distances.size();i++){ for(int j = i+1;j<distances.size();j++){ if(distances.get(i) < distances.get(j)){ temp = distances.get(i); distances.set(i, distances.get(j)); distances.set(j,temp); } } } } return distances; } }

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SCREENSHOTS :

As the change is only with the function part while comparing to above screenshots, sharing the screenshots of function implementation.

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OUTPUT :

Any doubts regarding this can be explained with pleasure :)