java – sorting arraylist of string in android-ThrowExceptions

Exception or error:

i am having a string arraylist ‘names’.which contains names of people.i want to sort the arraylist in alphabetical order.plz help me

How to solve:

This will solve your problem…

ArrayList arrayList = new ArrayList();

//Add elements to Arraylist
arrayList.add("1");
arrayList.add("3");
arrayList.add("5");
arrayList.add("2");
arrayList.add("4");


Collections.sort(arrayList);

//display elements of ArrayList
System.out.println("ArrayList elements after sorting in ascending order : ");
for(int i=0; i<arrayList.size(); i++)
    System.out.println(arrayList.get(i));

To sort an ArrayList object, use Collection.sort method. This is a
static method. It sorts an ArrayList object’s elements into ascending order.

Just in case if the below code in comment doesnt work means…
Try this code..

Create a custom comparator class:

import java.util.Comparator;

class IgnoreCaseComparator implements Comparator<String> {
  public int compare(String strA, String strB) {
    return strA.compareToIgnoreCase(strB);
  }
}

Then on your sort:

IgnoreCaseComparator icc = new IgnoreCaseComparator();

java.util.Collections.sort(arrayList,icc);

###

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

public class ArrayListSortExample {
public static void main(String[] args) {
/*
* Create a collections of colours
*/
List colours = new ArrayList();
colours.add("red");
colours.add("green");
colours.add("blue");
colours.add("yellow");
colours.add("cyan");
colours.add("white");
colours.add("black");

/*
* We can sort items of a list using the Collections.sort() method.
* We can also reverse the order of the sorting by passing the
* Collections.reverseOrder() comparator.
*/
Collections.sort(colours);
System.out.println(Arrays.toString(colours.toArray()));

Collections.sort(colours, Collections.reverseOrder());
System.out.println(Arrays.toString(colours.toArray()));
}

###

hi seethalakshmi for sorting on Arraylist you need comparator and collection

just go through this link http://ventrix.nsdc.gr/code_folds/?p=119, you can easily implement it

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