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It said "Be sure that the sort() method is able to sort arrays of different lengths."

Create an array of 20 numbers.
Populate it with numbers from the keyboard.
Display the five largest numbers.
Each value should be on a new line.

Requirements:

The program should display numbers on the screen.
The program should read values from the keyboard.
The Solution class must have two methods.
The sort() method should sort the array of numbers from highest to lowest.
The main() method should call the sort() method.
The program should display the five largest numbers in the array. Each value should be on a new line.

package com.codegym.task.task08.task0826; import java.io.BufferedReader; import java.io.InputStreamReader; /* Five winners */ public class Solution { public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); int[] array = new int[25]; for (int i = 0; i < array.length; i++) { array[i] = Integer.parseInt(reader.readLine()); } sort(array); System.out.println(array[0]); System.out.println(array[1]); System.out.println(array[2]); System.out.println(array[3]); System.out.println(array[4]); } public static void sort(int[] array) { //write your code here int temp = 0; for (int i = array.length-1; i > 0; i--) { for (int j = 1; j < i; j++) { if (array[j-1] < array[j]) { temp = array[j-1]; array[j-1] = array[j]; array[j] = temp; } } } } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

24 December 2018, 19:01

solution

The specific problem is that your second for loop never reaches the max index because j will be less than i and i starts at the max index. This means that the element at index arraylength-1 never gets touched. To fix this just make line 32 for (int j = 1; j <= i; j++). Of course, it is a lot easier to use the sort method that is already implemented in the Arrays class. This sorts from smallest to largest though. See code below:

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int[] array = new int[20];
        for (int i = 0; i < array.length; i++) {
            array[i] = Integer.parseInt(reader.readLine());
        }

        sort(array);

        for(int i = array.length-1; i > array.length-1-5; i--)
            System.out.println(array[i]);
    }

    public static void sort(int[] array) {
        //write your code here
        Arrays.sort(array);
    }
}

Sergei Polakov

Level 11 , Donets'k, Ukraine

15 May 2019, 19:13

insert your code ==== package com.codegym.task.task08.task0826; import java.io.BufferedReader; import java.io.InputStreamReader; import java.util.Arrays; /* Five winners */ public class Solution { public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); int[] array = new int[20]; for (int i = 0; i < array.length; i++) { array[i] = Integer.parseInt(reader.readLine()); } sort(array); for(int i = array.length-1; i > array.length-1-5; i--) System.out.println(array[i]); } public static void sort(int[] array) { //write your code here Arrays.sort(array); } } ----- but write mistakes The sort() method should sort the array of numbers from highest to lowest. RECOMMENDATION FROM YOUR MENTOR Be sure that the sort() method correctly sorts the array passed to it.

Guadalupe Gagnon

Level 37 , Tampa, United States

15 May 2019, 19:34

@Sergei The Arrays.sort method sorts in ascending order but the task asks for the array to be sorted in descending order. So instead of: 1, 2, 3, 4, 5, 6 it should be 6, 5, 4, 3, 2, 1 The actual elements in the array need to be in that order, not just what you out put to the screen.

Profj

Level 20 , Lagos, Nigeria

10 June 2019, 20:31

I don't know why this is not working for me

Xubres

Level 16 , Uranus, Space

23 December 2018, 16:44

useful

There is two mistakes I could find. Number 1 is the exercise says to create an array of 20 numbers, but you have 25. Number 2 if you print every element of the array, you will see that it gets sorted from max to min, but the last position is wrong, so there is some small mistake in the sort method and the last item of the array doesn't get sorted.

Peerawas

Level 18

24 December 2018, 15:02

Thanks for your reply :)