How to sort List? [duplicate]

Question

This question already has answers here:

How to sort an ArrayList? (18 answers)

Closed 6 years ago.

I have code and I have used list to store data. I want to sort data of it, then is there any way to sort data or shall I have to sort it manually by comparing all data?

import java.util.ArrayList; 
import java.util.List;

public class tes
{
    public static void main(String args[])
    {
        List<Integer> lList = new ArrayList<Integer>();
        lList.add(4);
        lList.add(1);
        lList.add(7);
        lList.add(2);
        lList.add(9);
        lList.add(1);
        lList.add(5);
        for(int i=0; i<lList.size();i++ )
        {
            System.out.println(lList.get(i));
        }
    }
}

Answer 1

To sort in ascending order :

Collections.sort(lList);

And for reverse order :

Collections.reverse(lList);

Answer 2

Use Collections class API to sort.

Collections.sort(list);

Answer 3

You can use the utility method in Collections class public static <T extends Comparable<? super T>> void sort(List<T> list) or

public static <T> void sort(List<T> list,Comparator<? super T> c)

Refer to Comparable and Comparator interfaces for more flexibility on sorting the object.

Answer 4

Just use Collections.sort(yourListHere) here to sort.

You can read more about Collections from here.

Answer 5

You can use Collections for to sort data:

import java.util.Collections;
import java.util.ArrayList;
import java.util.List;

public class tes
{
    public static void main(String args[])
    {
        List<Integer> lList = new ArrayList<Integer>();

        lList.add(4);       
        lList.add(1);
        lList.add(7);
        lList.add(2);
        lList.add(9);
        lList.add(1);
        lList.add(5);

        Collections.sort(lList);

        for(int i=0; i<lList.size();i++ )
        {
            System.out.println(lList.get(i));
        }

    }
}

Answer 6

Ascending order:

 Collections.sort(lList); 

Descending order:

Collections.sort(lList, Collections.reverseOrder());